AGREEMENT AND PLAN OF MERGER,

DATED AS OF OCTOBER 26, 2007
 
AMONG

AVIATION UPGRADE TECHNOLOGIES, INC., a Nevada corporation,

ONCOVISTA ACQUISITION CORP., a Delaware corporation

and

ONCOVISTA, INC., a Delaware corporation
 

--------------------------------------------------------------------------------

AGREEMENT AND PLAN OF MERGER, dated as of October 26, 2007 (the “Agreement”),
among AVIATION UPGRADE TECHNOLOGIES, INC., a Nevada corporation with executive
offices located at 14785 Omicron Drive, Suite 104, San Antonio, Texas 78245
(“AVUG”), ONCOVISTA ACQUISITION CORP., a Delaware corporation and a wholly-owned
subsidiary of AVUG with executive offices located at 14785 Omicron Drive, Suite
104, San Antonio, Texas 78245 (“Acquisition”), and ONCOVISTA, INC., a Delaware
corporation with executive offices located at 14785 Omicron Drive, Suite 104,
San Antonio, Texas 78245 (“OncoVista”). OncoVista, in its capacity as the
surviving corporation, is hereinafter sometimes referred to as the “Surviving
Corporation,” and Acquisition and OncoVista are hereinafter sometimes referred
to as the “Constituent Corporations”.

INTRODUCTION

Pursuant hereto, and subject to the terms hereof, the parties hereto intend that
OncoVista shall merge (the “Merger”) with Acquisition pursuant to Section 251 of
the General Corporation Law of the State of Delaware (the “DGCL”).
 

I.  NAME OF SURVIVING CORPORATION; CERTIFICATE OF
INCORPORATION AND BY-LAWS; BOARD OF DIRECTORS; OFFICERS
 
Section 1.01 Name of Surviving Corporation.  The corporation which shall survive
the Merger contemplated hereby is OncoVista.
 
Section 1.02 Certificate of Incorporation and By-laws. The certificate of
incorporation and the by-laws of OncoVista as in effect at the Effective Time
shall, from and after the Effective Time, be the certificate of incorporation
and the by-laws of the Surviving Corporation until they are amended.
 
Section 1.03 Board of Directors and Officers.

(a) The directors and officers of OncoVista at the Effective Time shall be the
directors and officers, respectively, of the Surviving Corporation, each to
serve, in each case (subject to the Surviving Corporation’s by-laws), until
their respective successors shall have been elected and qualified.

(b) The sole director of AVUG immediately prior to the Effective Time shall
appoint the directors of OncoVista at the Effective Time as the directors of
AVUG commencing at the close of business on the last day of the Gap Period, each
to serve, in each case (subject to the by-laws of AVUG), until their respective
successors shall have been elected and qualified. The sole director of AVUG
immediately prior to the Effective Time shall appoint the officers of OncoVista
at the Effective Time as the officers of AVUG commencing at the Effective Time,
each to serve, in each case (subject to the by-laws of AVUG), until their
respective successors shall have been elected and qualified.  For purposes of
this Agreement, the term “Gap Period” shall mean the period commencing at the
Effective Time and terminating on the tenth day following the transmission by
AVUG to the holders of record of securities of AVUG the information referenced
in Section 5.02(m) of this Agreement. 

--------------------------------------------------------------------------------

II. STATUS AND CONVERSION OF SECURITIES
 
Section 2.01 Stock of OncoVista. 

(a) Each share of common stock of OncoVista (“OncoVista Common Stock”)
outstanding at the Effective Time shall, subject to compliance with Section
2.01(d), be converted into and exchanged for one share of common stock of AVUG
(giving effect to the Stock Split as hereinafter defined, “AVUG Common Stock”).

(b) Notwithstanding Section 2.01(a) of this Agreement, merger consideration
shall not be issued in respect of any shares of OncoVista Common Stock, the
holders of which shall object to the Merger in writing and demand payment of the
value of their shares of OncoVista Common Stock pursuant to, and in accordance
with, Section 262 of the DGCL and as a result payment therefor is made. Such
holders shall have only the rights provided by such Section 262.

(c) Subject to the provisions of Section 2.01(b) of this Agreement, after the
Effective Time, each holder of an outstanding certificate or certificates (the
“Old Certificates”) theretofore representing shares of OncoVista Common Stock,
upon surrender thereof to Interwest Transfer Company, Inc. (the “Exchange
Agent”), shall be entitled to receive in exchange therefor a certificate or
certificates (the “New Certificates”) for the number of shares of AVUG Common
Stock represented by such Old Certificate or Old Certificates, which AVUG agrees
to make available to the Exchange Agent as soon as practicable after the
Effective Time, representing the number of shares of AVUG Common Stock into and
for which the shares of OncoVista Common Stock theretofore represented by such
surrendered Old Certificates have been converted. No certificates or scrip for
fractional shares of AVUG Common Stock will be issued, no AVUG stock split or
dividend shall relate to any fractional share interest, and no such fractional
share interest shall entitle the owner thereof to vote or to any rights of a
stockholder of AVUG. In lieu of the issuance or recognition of fractional shares
of AVUG Common Stock or interests or rights therein, the Exchange Agent shall
round such fraction to the next higher whole number of shares of AVUG Common
Stock. Until surrendered and exchanged, each Old Certificate shall after the
Effective Time be deemed for all corporate purposes, other than the payment of
dividends or liquidating or other distributions, if any, to holders of record of
AVUG Common Stock, to represent only the right to receive the number of shares
of AVUG Common Stock into and for which the shares of OncoVista Common Stock
theretofore represented by such Old Certificate shall have been converted. No
dividend or liquidating or other distribution, if any, payable to holders of
record of shares of OncoVista Common Stock at or after the Effective Time on
shares of AVUG Common Stock, or payable subsequent to the Effective Time to
holders of record of shares of OncoVista Common Stock at a time prior to the
Effective Time shall be paid to the holders of Old Certificates; provided,
however, that upon surrender and exchange of such Old Certificates there shall
be paid (subject to the last sentence of this Section 2.01(c)) to the record
holders of the New Certificates issued in exchange therefor (i) the amount,
without interest thereon, of dividends and liquidating or other distributions,
if any, which theretofore have become payable to holders of record of shares of
OncoVista Common Stock on or after the Effective Time with respect to the number
of whole shares of AVUG Common Stock represented by such New Certificates and
(ii) the amount, without interest thereon, of dividends and liquidating or other
distributions, if any, declared by OncoVista payable to holders of record of
shares of OncoVista Common Stock at a time prior to the Effective Time, but
payable subsequent to the Effective Time.  If outstanding Old Certificates are
not surrendered and exchanged for shares of AVUG Common Stock pursuant hereto
prior to two years after the Effective Time (or, in any particular case, prior
to the date before the second anniversary of the Effective Time on which the
shares of AVUG Common Stock pursuant hereto and the dividends and liquidating or
other distributions, if any, would otherwise escheat to, or become the property
of, any governmental unit or any agency thereof), then the following shall
become the property of AVUG (and, to the extent not in its possession, shall be
paid over to it), free and clear of all claims or interest of any other person
previously entitled thereto: (i) the number of whole shares of AVUG Common Stock
into and for which the shares of OncoVista Common Stock theretofore represented
by such Old Certificates shall have been converted, (ii) the amount of dividends
and liquidating or other distributions, if any, which theretofore have become
payable to holders of record on or after the Effective Time with respect to such
number of whole shares of AVUG Common Stock, (iii) the amount of dividends and
liquidating or other distributions, if any, declared by OncoVista payable to
holders of record of shares of OncoVista Common Stock at a time prior to the
Effective Time, but payable subsequent to the Effective Time, and (iv) the
amount of dividends and liquidating or other distributions, if any, which
subsequently become payable with respect to such number of whole shares of AVUG
Common Stock.
 
2

--------------------------------------------------------------------------------

(d) If any New Certificate is to be issued in a name other than that in which
the Old Certificate surrendered for exchange is issued, the Old Certificate so
surrendered shall be properly endorsed and otherwise in proper form for transfer
and the person requesting such exchange shall pay to the Exchange Agent any
transfer or other taxes required by reason of the issuance of the New
Certificate in any name other than that of the registered holder of the Old
Certificate surrendered, or establish to the satisfaction of the Exchange Agent
that such tax has been paid or is not payable.

(e) As of the Effective Time, no transfer of the shares of OncoVista Common
Stock outstanding prior to the Effective Time shall be made on the stock
transfer books of the Surviving Corporation. If, after the Effective Time, Old
Certificates are presented to AVUG or the Surviving Corporation, they shall be
exchanged pursuant to Section 2.01(c).

3

--------------------------------------------------------------------------------

Section 2.02 OncoVista Stock Options, OncoVista Warrants and OncoVista Notes.  

(a) At the Effective Time, AVUG shall assume each option (each a “OncoVista
Stock Option”) outstanding at the Effective Time granted by OncoVista prior to
the Effective Time by executing and delivering to such holder an assumption and
AVUG shall be substituted for OncoVista with respect to each OncoVista Stock
Option so assumed, and thereafter, until any event that affects the exercise
price, each OncoVista Stock Option assumed by AVUG as aforesaid shall represent
an option to purchase, instead of OncoVista Common Stock, the number of whole
shares of AVUG Common Stock which equals the number of shares of OncoVista
Common Stock subject to such option immediately prior to the Effective Time; and
the price per share of AVUG Common Stock at which such option shall be
exercisable shall (until any event that affects the exercise price) be an amount
(to the next higher whole cent) equal to the option price per share of OncoVista
Common Stock immediately prior to the Effective Time. Except as aforesaid, the
period during which, and the terms upon which, each OncoVista Stock Option may
be exercised shall remain unchanged.

(b) At the Effective Time, AVUG shall assume each warrant (each a “OncoVista
Warrant”) outstanding at the Effective Time granted or sold by OncoVista prior
to the Effective Time by executing and delivering to such holder an assumption
and AVUG shall be substituted for OncoVista with respect to each OncoVista
Warrant so assumed, and thereafter, until any event that affects the exercise
price, each OncoVista Warrant assumed by AVUG as aforesaid shall represent an
option to purchase, instead of OncoVista Common Stock, the number of whole
shares of AVUG Common Stock which equals the number of shares of OncoVista
Common Stock subject to such option immediately prior to the Effective Time; and
the price per share of AVUG Common Stock at which such option shall be
exercisable shall (until any event that affects the exercise price) be an amount
(to the next higher whole cent) equal to the option price per share of OncoVista
Common Stock immediately prior to the Effective Time. Except as aforesaid, the
period during which, and the terms upon which, each OncoVista Warrant may be
exercised shall remain unchanged.
 
(c) At the Effective Time, each note convertible into OncoVista Common Stock
outstanding at the Effective Time granted or sold by OncoVista prior to the
Effective Time (each an “OncoVista Note”) shall be convertible into, instead of
OncoVista Common Stock, the number of whole shares of AVUG Common Stock which
equals the number of shares of OncoVista Common Stock subject to such
convertible note immediately prior to the Effective Time; and the price per
share of AVUG Common Stock at which such convertible note shall be convertible
shall (until any event that affects the conversion price) be an amount (to the
next higher whole cent) equal to the conversion price per share of OncoVista
Common Stock immediately prior to the Effective Time. Except as aforesaid, the
period during which, and the terms upon which, each OncoVista Note may be
exercised shall remain unchanged.
 
Section 2.03 Affiliates of OncoVista. Each of OncoVista and AVUG agrees that it
will use its best efforts to avoid violating the securities laws of the United
States or of any state or other jurisdiction while pursuing the Merger and the
other transactions contemplated hereby.

Section 2.04 Capital Stock of AVUG.  Except as contemplated by this Agreement,
all issued shares of AVUG Common Stock, whether outstanding or held in the
treasury of AVUG, shall continue unchanged as shares of capital stock of AVUG.
All shares of AVUG Common Stock held beneficially or of record by OncoVista at
the Effective Time shall be deemed to be immediately cancelled at the Effective
Time and shall become authorized, but unissued shares of AVUG Common Stock.

4

--------------------------------------------------------------------------------

Section 2.05 Capital Stock of Acquisition. All issued shares of capital stock of
Acquisition (“Acquisition Capital Stock”) outstanding at the Effective Time
shall be converted into and exchanged for ten shares of common stock of the
Surviving Corporation, except that shares of capital stock of Acquisition held
in Acquisition’s treasury shall be canceled.
 
III. STOCKHOLDER APPROVALS; BOARD OF DIRECTORS’
RECOMMENDATIONS; FILING; EFFECTIVE TIME

Section 3.01 Stockholder Approvals; Board of Directors’ Recommendations.
Meetings of the stockholders of Acquisition and of OncoVista shall be held in
accordance with the law of their respective jurisdiction of incorporation (or
actions by written consent in lieu of a meeting of stockholders shall be
executed in accordance with the law of their respective jurisdiction of
incorporation) as promptly as possible, after at least 10 days’ prior written
notice thereof to the stockholders of the respective corporations in the case of
a meeting of stockholders, in each case, among other things, to consider and
vote upon the adoption and approval of this Agreement, the Merger, and the other
transactions contemplated by this Agreement. AVUG, as the sole stockholder of
Acquisition, shall, prior to the Effective Time, vote all shares of capital
stock of Acquisition in favor of the adoption and approval of this Agreement,
the Merger, and the other transactions contemplated hereby. In the event that
the stockholders of AVUG are required to approve the Merger, subject to Section
2.03 hereof and its fiduciary duty to stockholders, the Board of Directors of
AVUG shall recommend to its stockholders that this Agreement, the Merger, and
the other transactions contemplated hereby be adopted and approved.

Section 3.02 Filing; Effective Time. As soon as practicable after the adoption
and approval of this Agreement, the Merger, and the other transactions
contemplated by the respective stockholders of each of AVUG, Acquisition, and
OncoVista (as applicable) (unless one or more of the conditions contained in
Articles VII and VIII hereof have not then been fulfilled or waived, then as
soon as practicable after the fulfillment or waiver of all such conditions), an
appropriate certificate of merger in the form required by the DGCL shall be
executed and filed in the office of the Secretary of State of the State of
Delaware, at which time the Merger shall become effective (the “Effective
Time”).

5

--------------------------------------------------------------------------------

IV. CERTAIN EFFECTS OF MERGER

Section 4.01 Effects Under the DGCL.  When the Merger becomes effective, the
separate existence of Acquisition shall cease, Acquisition shall be merged into
OncoVista, and the Surviving Corporation shall possess all the rights,
privileges, powers, and franchises as well of a public as of a private nature,
and shall be subject to all the restrictions, disabilities, and duties of each
of the Constituent Corporations; and all and singular, the rights, privileges,
powers, and franchises of each of the Constituent Corporations, and all
property, real, personal, and mixed, and all debts due to either of the
Constituent Corporations on whatever account, as well for stock subscriptions as
all other things in action or belonging to each of the Constituent Corporations
shall be vested in the Surviving Corporation; and all property, rights,
privileges, powers, and franchises, and all and every other interest shall be
thereafter as effectually the property of the Surviving Corporation as they were
of the several and respective Constituent Corporations; and the title to any
real estate vested by deed or otherwise, under the laws of the State of Delaware
or any other jurisdiction, in either of the Constituent Corporations, shall not
revert or be in any way impaired by reason of the Merger; but all rights of
creditors and all liens upon any property of either of the Constituent
Corporations shall be preserved unimpaired, and all debts, liabilities, and
duties of the respective Constituent Corporations shall thenceforth attach to
the Surviving Corporation, and may be enforced against it to the same extent as
if such debts, liabilities, and duties had been incurred or contracted by it.

Section 4.02 Reorganization. The Merger is intended to qualify as a
reorganization within the meaning of Section 368 of the United States Internal
Revenue Code of 1986, as amended (the “Code”), and this Agreement is intended to
be a “plan of reorganization” within the meaning of the regulations promulgated
under Section 368 of the Code.
 
 V. COVENANTS

Section 5.01 Covenants of OncoVista. OncoVista agrees that, unless AVUG
otherwise agrees in writing:

(a) Until the earlier of the Effective Time and the abandonment or termination
of the Merger pursuant to Article VII or Article VIII or otherwise (the “Release
Time”), no amendment will be made in the certificate of incorporation or by-laws
of OncoVista.

(b) Until the Release Time, no dividend or liquidating or other distribution or
stock split shall be authorized, declared, paid, or effected by OncoVista in
respect of the outstanding shares of OncoVista Common Stock. Until the Release
Time, no direct or indirect redemption, purchase, or other acquisition shall be
made by OncoVista of shares of OncoVista Common Stock.

(c) Until the Release Time, OncoVista will afford the officers, directors,
employees, counsel, agents, investment bankers, accountants, and other
representatives of AVUG and lenders, investors, and prospective lenders and
investors free and full access to the plants, properties, books, and records of
OncoVista, will permit them to make extracts from and copies of such books and
records, and will from time to time furnish AVUG with such additional financial
and operating data and other information as to the financial condition, results
of operations, businesses, properties, assets, liabilities, or future prospects
of OncoVista as AVUG from time to time may request.

6

--------------------------------------------------------------------------------

(d) Until the Release Time, OncoVista will conduct its affairs so that at the
Effective Time no representation or warranty of OncoVista will be inaccurate, no
covenant or agreement of OncoVista will be breached, and no condition in this
Agreement will remain unfulfilled by reason of the actions or omissions of
OncoVista. Except as otherwise consented to by AVUG in writing, until the
Release Time, OncoVista will use its best efforts to preserve the business
operations of OncoVista intact, to keep available the services of its present
personnel, to preserve in full force and effect the contracts, agreements,
instruments, leases, licenses, arrangements, and understandings of OncoVista,
and to preserve the good will of its suppliers, customers, and others having
business relations with any of them. Until the Release Time, OncoVista will
conduct its affairs in all respects only in the ordinary course, other than in
connection with the matters referenced herein.

(e) Until the Release Time, OncoVista will immediately advise AVUG in a detailed
written notice of any material fact or occurrence or any pending or threatened
material occurrence of which it obtains knowledge and which (if existing and
known at the date of the execution of this Agreement) would have been required
to be set forth or disclosed in or pursuant to this Agreement which (if existing
and known at any time prior to or at the Effective Time) would make the
performance by any party of a covenant contained in this Agreement impossible or
make such performance materially more difficult than in the absence of such fact
or occurrence, or which (if existing and known at the time of the Effective
Time) would cause a condition to any party’s obligations under this Agreement
not to be fully satisfied.

(f) OncoVista shall use its commercially reasonable efforts to insure that all
confidential information which OncoVista or any of its respective officers,
directors, employees, counsel, agents, investment bankers, or accountants may
now possess or may hereafter create or obtain relating to the financial
condition, results of operations, businesses, properties, assets, liabilities,
or future prospects of OncoVista, any affiliate of OncoVista, or any customer or
supplier of any of them or any such affiliate shall not be published, disclosed,
or made accessible by any of them to any other person or entity at any time or
used by any of them except in the ordinary course of business and for the
benefit of OncoVista; provided, however, that the restrictions of this sentence
shall not apply (A) after the Merger is abandoned or terminated pursuant to
Article VII or Article VIII or otherwise, (B) as may otherwise be required by
law, (C) as may be necessary or appropriate in connection with the enforcement
of this Agreement, or (D) to the extent the information shall have otherwise
become publicly available.

(g) Before OncoVista releases any information concerning this Agreement, the
Merger, or any of the other transactions contemplated by this Agreement which is
intended for, or may result in, public dissemination thereof, OncoVista shall
cooperate with AVUG, shall furnish drafts of all documents or proposed oral
statements to AVUG for comment, and shall not release any such information
without the written consent of AVUG, which consent shall not be unreasonably
withheld. Nothing contained herein shall prevent OncoVista from releasing any
information if required to do so by law.

(h) OncoVista shall not make any agreement or reach any understanding not
approved in writing by AVUG as a condition for obtaining any consent,
authorization, approval, order, license, certificate, or permit required for the
consummation of the transactions contemplated by this Agreement.

7

--------------------------------------------------------------------------------

(i) OncoVista shall furnish, or cause to be furnished, for inclusion in the
periodic reports of AVUG on Forms 8-K, 10-Q, 10-K, or otherwise (such periodic
reports, together with all financial statements, exhibits, amendments, and
supplements thereto, in the form filed by AVUG with the Securities and Exchange
Commission (the “SEC”) being hereinafter called the “Periodic Reports”), to be
filed pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange
Act”), in connection with the Merger, or for inclusion in AVUG’s filings under
state “blue-sky,” securities, or take-over laws, such information about
OncoVista or OncoVista’s security holders as may be required or as may be
reasonably requested by AVUG, and shall continue to furnish or cause to be
furnished such information as is necessary to keep such information correct and
complete in all material respect until the Release Time. OncoVista represents
and warrants that the information that it has furnished to date, taken as a
whole, does not now, and will not at any time prior to the Release Time, (i)
contain an untrue statement of a material fact or (ii) omit to state a material
fact required to be stated therein or necessary to make the statements therein
not false or misleading.
 
(j) OncoVista shall timely prepare and file any declaration or filing necessary
to comply with any transfer tax statutes that require any such filing before the
Effective Time.
 
Section 5.02 Covenants of AVUG and Acquisition. AVUG and Acquisition each agrees
that, unless OncoVista otherwise agrees in writing:
 
(a) (i) Until the Release Time, no dividend or liquidating or other distribution
or stock split shall be authorized, declared, paid, or effected by AVUG in
respect of the outstanding shares of AVUG Common Stock, except for a forward
split of 1.4739739-for-one effected on October 22, 2007 (the “Stock Split”).

8

--------------------------------------------------------------------------------

 
(ii) Until the Release Time, except as contemplated by this Agreement, no share
of capital stock of AVUG or warrant for any such share, right to subscribe to or
purchase any such share, or security convertible into, or exchangeable or
exercisable for, any such share, shall be issued or sold by AVUG.

(b) Until the Release Time, AVUG and Acquisition will afford the officers,
directors, employees, counsel, agents, investment bankers, accountants, and
other representatives of OncoVista free and full access to the plants,
properties, books, and records of AVUG and Acquisition, will permit them to make
extracts from and copies of such books and records, and will from time to time
furnish OncoVista with such additional financial and operating data and other
information as to the financial condition, results of operations, businesses,
properties, assets, liabilities, or future prospects of AVUG and Acquisition as
OncoVista from time to time may request.

(c) Until the Release Time, AVUG and Acquisition will conduct their respective
affairs, so that at the Effective Time no representation or warranty of AVUG or
Acquisition will be inaccurate, no covenant or agreement of AVUG or Acquisition
will be breached, and no condition in this Agreement will remain unfulfilled by
reason of the actions or omissions of AVUG. Until the Release Time, Acquisition
will conduct no affairs except in connection with this Agreement, the Merger, or
any of the other transactions contemplated by this Agreement. Except as
otherwise consented to by OncoVista in writing and except as otherwise
contemplated by this Agreement, until the Release Time and until the expiration
of the Gap Period, AVUG will conduct its affairs in all respects only in the
ordinary course.

(d) Until the Release Time, AVUG will immediately advise OncoVista in a detailed
written notice of any material fact or occurrence or any pending or threatened
material occurrence of which it obtains knowledge and which (if existing and
known at the date of the execution of this Agreement) would have been required
to be set forth or disclosed in or pursuant to this Agreement or in any schedule
hereto, which (if existing and known at any time prior to or at the Effective
Time) would make the performance by any party of a covenant contained in this
Agreement impossible or make such performance materially more difficult than in
the absence of such fact or occurrence, or which (if existing and known at the
time of the Effective Time) would cause a condition to any party’s obligations
under this Agreement not to be fully satisfied.

(e) Each of AVUG and Acquisition shall use its commercially reasonable efforts
to insure that all confidential information which AVUG, Acquisition, or any of
their respective officers, directors, employees, counsel, agents, investment
bankers, or accountants may now possess or may hereafter create or obtain
relating to the financial condition, results of operations, businesses,
properties, assets, liabilities, or future prospects of OncoVista, any affiliate
of OncoVista, or any customer or supplier of or any such affiliate shall not be
published, disclosed, or made accessible by any of them to any other person or
entity without the prior written consent of OncoVista, which written consent
shall not be unreasonably withheld; provided, however, that the restrictions of
this sentence shall not apply (i) as may otherwise be required by law, (ii) as
may be necessary or appropriate in connection with the enforcement of this
Agreement, or (iii) to the extent the information shall have otherwise become
publicly available. AVUG and Acquisition shall, and shall cause all other such
persons and entities to, deliver to OncoVista all tangible evidence of the
confidential information relating to OncoVista, any affiliate of OncoVista, or
(insofar as such confidential information was provided by, or on behalf of,
OncoVista, or any such affiliate of OncoVista) any customer or supplier of any
of them or any such affiliate to which the restrictions of the foregoing
sentence apply immediately after the abandonment or termination of the Merger
pursuant to Article VII or Article VIII or otherwise.
 
9

--------------------------------------------------------------------------------

 
(f) Before AVUG or Acquisition releases any information concerning this
Agreement, the Merger, or any of the other transactions contemplated by this
Agreement which is intended for or may result in public dissemination thereof,
AVUG and Acquisition shall cooperate with OncoVista, shall furnish drafts of all
documents or proposed oral statements to OncoVista for comment, and shall not
release any such information without the written consent of OncoVista. Nothing
contained herein shall prevent AVUG or Acquisition from releasing any
information if required to do so by law.

(g) Neither AVUG nor Acquisition shall make any agreement or reach any
understanding not approved in writing by OncoVista as a condition for obtaining
any consent, authorization, approval, order, license, certificate, or permit
required for the consummation of the transactions contemplated by this
Agreement.

(h) AVUG and Acquisition shall promptly prepare all required or, in the
reasonable opinion of the parties hereto, appropriate Periodic Reports relating
to this Agreement, the Merger, and the other transactions contemplated hereby
and in connection herewith. AVUG and Acquisition each shall furnish or cause to
be furnished, for inclusion in the Periodic Reports, such information about
AVUG, Acquisition, and AVUG’s security holders as may be required or as may be
reasonably requested by OncoVista, and shall continue to furnish or cause to be
furnished such information as is necessary to keep such information correct and
complete in all material respects until the Release Time. AVUG and Acquisition
each represents and warrants that the information that it has furnished to date,
taken as a whole, does not now, and will not at any time prior to the Release
Time, (i) contain an untrue statement of a material fact or (ii) omit to state a
material fact required to be stated therein or necessary to make the statements
therein not false or misleading. AVUG and Acquisition each shall also take any
action required to be taken by it under state “blue-sky,” securities, or
take-over laws in connection with the issuance of AVUG Common Stock pursuant to
the Merger. The filings made by AVUG since January 1, 2004 with the SEC were, if
filed under the Exchange Act, prepared in accordance with the then existing
requirements of the Exchange Act and the rules and regulations thereunder and,
if filed under the Securities Act, prepared in accordance with the then existing
requirements of the Securities Act and the rules and regulations thereunder.
Such filings when filed, and the press releases and other public statements AVUG
has made subsequent to the last such filing when considered together with such
filings, did not at the time of filing or issuance of the press releases or
other public statements, as the case may be, and (with respect to the press
releases and other public statements, when considered together with such
filings) do not now (i) contain an untrue statement of a material fact or (ii)
omit to state a material fact required to be stated therein or necessary to make
the statements therein not false or misleading.
 
10

--------------------------------------------------------------------------------

 
(i) If, prior to the Release Time, AVUG Common Stock shall be recapitalized or
reclassified or AVUG shall effect any stock dividend, stock split, or reverse
stock split of AVUG Common Stock (other than the Stock Split), then the shares
of AVUG Common Stock to be delivered under this Agreement or upon exercise,
conversion, or exchange of any security to be delivered under this Agreement or
assumed by AVUG as contemplated by this Agreement shall be appropriately and
equitably adjusted to the kind and amount of shares of stock and other
securities and property to which the holders of such shares of AVUG Common Stock
or such other security would have been entitled to receive had such stock or
such other security been issued and outstanding as of the record date for
determining stockholders entitled to participate in such corporate event.

(j) AVUG shall timely prepare and file any declaration or filing necessary to
comply with any transfer tax statutes that require any such filing before the
Effective Time.

(k) (i)  Following the Merger, AVUG will cause Surviving Corporation to continue
OncoVista’s historic business or to use a significant portion of OncoVista’s
historic business assets in a business, in each case within the meaning of
section 1.368-1(d) of the Treasury Regulations, assuming that the assets of, and
the business conducted by, OncoVista at the Effective Time constitute
OncoVista’s historic business assets and historic business, respectively.
 
(ii)  Following the Merger, AVUG will not permit Surviving Corporation to issue
additional shares that would result in AVUG losing control of Surviving
Corporation within the meaning of section 368(c) of the Code.
 
(l) At or prior to the Effective Time, AVUG shall apply with the relevant
Department of the State of Nevada for a “dba” to do business under the assumed
name of “OncoVista Innovative Therapies, Inc.” As soon as is reasonably
practicable thereafter, AVUG shall file a proxy or information statement with
the SEC for delivery to stockholders to consider and act upon resolutions
adopted by the Board of Directors of AVUG to change the domicile of AVUG to the
State of Delaware and its name to “OncoVista Innovative Therapies, Inc.” or such
other state and such other name as shall be selected by resolutions of the newly
designated and elected Board of Directors of AVUG.
 

(m) 14f-1 Information. As soon as practicable following the Effective Time, AVUG
shall file with the SEC and transmit to its holders of record the information
required by Rule 14f-1 under the Exchange Act, which filing and information
shall be satisfactory in form and substance to counsel of OncoVista.

(n) Commencing at the Effective Time, AVUG and Acquisition agree to indemnify
and hold harmless OncoVista and OncoVista’s officers, directors, employees,
agents, and counsel, in each case past, present, or as they may exist at any
time after the date of this Agreement, and each person, if any, who controls,
controlled, or will control OncoVista (collectively the “OncoVista Indemnitees”)
within the meaning of Section 15 of the Securities Act or Section 20(a) of the
Exchange Act, and, if the Merger is abandoned or terminated pursuant to Article
VII or Article VIII or otherwise except solely as a result of a breach of this
Agreement by OncoVista, against any and all losses, liabilities, claims,
damages, and expenses whatsoever (which shall include, for all purposes of this
Section 5.02(n) of this Agreement, but not be limited to reasonable counsel fees
and any and all reasonable expenses whatsoever incurred in investigating,
preparing, or defending against any litigation, commenced or threatened, or any
claim whatsoever, and any and all amounts paid in settlement of any claim or
litigation, in each case whether or not involving a third party) as and when
incurred, arising out of, based upon, or in connection with (i) any untrue
statement or alleged untrue statement of a material fact contained in (A)
Periodic Reports or any amendment or supplement thereto or (B) any application
or other document or communication filed with any governmental authority in
connection with the Merger or filed with any securities exchange; or any
omission or alleged omission to state a material fact required to be stated
therein or necessary to make the statements therein not misleading, provided in
each case that such untrue statement, alleged untrue statement, omission, or
alleged omission relates to information furnished by, or on behalf of, or
pertaining to, AVUG or Acquisition or AVUG or Acquistion security holder, or
(ii) any breach of any representation, warranty, covenant, or agreement of AVUG
or Acquistion contained in this Agreement. The foregoing agreement to indemnify
shall be in addition to any liability AVUG or Acquisition may otherwise have,
including liabilities arising under this Agreement.
 
REPRESENTATIONS AND WARRANTIES

Section 6.01 Certain Representations and Warranties of OncoVista. OncoVista
represents and warrants to AVUG and Acquisition as follows:
 
(a) (i) The information contained in OncoVista’s private placement memorandum
dated July 25, 2007, as amended by Supplement No. 1 thereto, dated July 30, 2007
(the “PPM”) is accurate, complete, and correct in all material respects and does
not contain or omit any information that would make the information contained
therein misleading in any material respects. Since July 25, 2007:
 
11

--------------------------------------------------------------------------------

 
(A) There has at no time been a material adverse change in the financial
condition, results of operations, businesses, properties, assets, liabilities,
or future prospects of OncoVista;
 
(B) OncoVista has not authorized, declared, paid, or effected any dividend or
liquidating or other distribution in respect of its capital stock or any direct
or indirect redemption, purchase, or other acquisition of any stock of
OncoVista; and
 
(C) Except as set forth in the PPM, the operations and businesses of OncoVista
have been conducted in all respects only in the ordinary course, except:
 
(1) OncoVista sold an aggregate of 970,712 units in the offering described in
the PPM; and
 
(2) Without giving effect to the Stock Split, OncoVista acquired an aggregate of
10,963,851 shares of AVUG Common Stock, representing approximately 95.7% of the
issued and outstanding AVUG Common Stock;
 
(3)  OncoVista discontinued its preclinical development of targeted
nanoparticles (OVI-111).
 
(ii) After the Effective Time, OncoVista will maintain disclosure controls and
procedures required by Rule 13a-15 or 15d-15 under the Exchange Act and
OncoVista believes that such controls and procedures will be effective to ensure
that:

(A) all material information concerning OncoVista will be made known on a timely
basis to the individuals to be responsible for the preparation of AVUG’s filings
with the SEC and other public disclosure documents following the Effective Time;

(B) transactions will be executed in accordance with management’s general or
specific authorizations;
 
(C) transactions will be recorded as necessary to permit preparation of
financial statements in accordance with generally accepted accounting principles
and to maintain asset accountability;

(D) access to assets will be permitted only in accordance with management’s
general or specific authorization; and

(E)  the recorded accountability for assets will be compared with the existing
assets at reasonable intervals and appropriate action will be taken with respect
to any differences.

(iii) OncoVista has made available to AVUG copies of, all written descriptions
of, and all policies, manuals and other documents promulgating, such disclosure
controls and procedures.  The books, records and accounts of OncoVista
accurately and fairly reflect, in reasonable detail, the transactions in, and
dispositions of, the assets of, and the results of operations of, OncoVista all
to the extent required by generally accepted accounting principles.  
 
12

--------------------------------------------------------------------------------

 
(c) Other than as disclosed on Schedule 6.01(c), OncoVista has no subsidiaries
or affiliated corporation or owns any interest in any other enterprise (whether
or not such enterprise is a corporation) (such entities disclosed in Schedule
6.01(c), the “OncoVista Subsidiaries”). OncoVista and each OncoVista Subsidiary
has been duly organized and is validly existing as a corporation in good
standing under the laws of its respective jurisdiction of incorporation or
formation, with full power and authority (corporate and other) to own, lease and
operate its respective properties and conduct its respective business; except as
otherwise disclosed on Schedule 6.01(c), OncoVista and each OncoVista Subsidiary
is duly qualified to do business as a foreign corporation and is in good
standing in each jurisdiction in which the ownership or leasing of its
respective properties or the conduct of its respective business requires such
qualification, except where the failure to be so qualified or be in good
standing would not have a material adverse effect on the business, prospects,
condition (financial or otherwise), and results of operations of OncoVista and
the OncoVista Subsidiaries taken as a whole; no proceeding has been instituted
in any such jurisdiction, revoking, limiting or curtailing, or seeking to
revoke, limit or curtail, such power and authority or qualification; OncoVista
and each OncoVista Subsidiary is in possession of, and operating in compliance
with, all authorizations, licenses, certificates, consents, orders and permits
from state, federal, foreign and other regulatory authorities that are material
to the conduct of its respective business, all of which are valid and in full
force and effect; neither OncoVista nor any OncoVista Subsidiary is in violation
of its respective charter or bylaws or in default in the performance or
observance of any obligation, agreement, covenant or condition contained in any
material bond, debenture, note or other evidence of indebtedness, or in any
material lease, contract, indenture, mortgage, deed of trust, loan agreement,
joint venture or other agreement or instrument to which it is a party or by
which it or its respective properties or assets may be bound, which violation or
default would have a material adverse effect on the business, prospects,
financial condition or results of operations of OncoVista and the OncoVista
Subsidiaries taken as a whole; and neither OncoVista nor any OncoVista
Subsidiaries is in violation of any law, order, rule, regulation, writ,
injunction, judgment or decree of any court, government or governmental agency
or body, domestic or foreign, having jurisdiction thereover or over its
respective properties or assets, which violation would have a material adverse
effect on the business, prospects, financial condition or results of operations
of OncoVista and the OncoVista Subsidiaries taken as a whole.
 
(d) OncoVista has all requisite power and authority to execute, deliver, and
perform this Agreement. Except as set forth in this Agreement, all necessary
proceedings of OncoVista have been duly taken to authorize the execution,
delivery, and performance of this Agreement thereby. This Agreement has been
duly authorized, executed, and delivered by OncoVista, constitutes the legal,
valid, and binding obligation of OncoVista, and is enforceable as to OncoVista
in accordance with its respective terms. Except as otherwise set forth in this
Agreement, no consent, authorization, approval, order, license, certificate, or
permit of or from, or declaration or filing with, any federal, state, local, or
other governmental authority or any court or other tribunal is required by
OncoVista or any OncoVista Subsidiary for the execution, delivery, or
performance of this Agreement thereby. No consent, approval, authorization or
order of, or qualification with, any court, government or governmental agency or
body, domestic or foreign, having jurisdiction over OncoVista, any OncoVista
Subsidiary, or over its respective properties or assets is required for the
execution and delivery of this Agreement and the consummation by OncoVista of
the transactions herein and therein contemplated, except such as may be required
under the Securities Act or under state or other securities or blue sky laws,
all of which requirements have been, or in accordance therewith will be,
satisfied in all material respects. No consent of any party to any material
contract, agreement, instrument, lease, license, arrangement, or understanding
to which OncoVista or any OncoVista Subsidiary is a party, or to which it or any
of its respective businesses, properties, or assets are subject, is required for
the execution, delivery, or performance of this Agreement; and the execution,
delivery, and performance of this Agreement will not violate, result in a breach
of, conflict with, or (with or without the giving of notice or the passage of
time or both) entitle any party to terminate or call a default under, entitle
any party to receive rights or privileges that such party was not entitled to
receive immediately before this Agreement was executed under, or create any
obligation on the part of OncoVista, the Surviving Corporation, or any OncoVista
Subsidiary to which it was not subject immediately before this Agreement was
executed under, any term of any such material contract, agreement, instrument,
lease, license, arrangement, or understanding, or violate or result in a breach
of any term of the certificate of incorporation or by-laws or analogous
governing document of OncoVista or any OncoVista Subsidiary or (if the
provisions of this Agreement are satisfied) violate, result in a breach of, or
conflict with any law, rule, regulation, order, judgment, decree, injunction, or
writ of any court, government or governmental agency or body, domestic or
foreign, having jurisdiction over OncoVista or any OncoVista Subsidiary or over
its respective properties or assets.
 
13

--------------------------------------------------------------------------------

 
(e) There is not any pending or, to OncoVista’s knowledge, threatened, action,
suit, claim or proceeding against OncoVista or any OncoVista Subsidiary, or any
of the officers of either of the foregoing, or any of the respective properties,
assets or rights of OncoVista or any OncoVista Subsidiary, before any court,
government or governmental agency or body, domestic or foreign, having
jurisdiction over OncoVista or any OncoVista Subsidiary or over the officers or
the properties of either of the foregoing, or otherwise that (i) is reasonably
likely to result in any material adverse change in the respective business,
prospects, financial condition or results of operations of OncoVista and the
OncoVista Subsidiaries taken as a whole or might materially and adversely affect
their properties, assets or rights taken as a whole, (ii) might prevent
consummation of the transactions contemplated by this Agreement, or (iii)
alleging violation of any Federal or state securities laws.
 
(f) The authorized capital stock of OncoVista consists of 30,000,000 shares of
Common Stock, of which 16,888,427 shares of Common Stock are outstanding. Each
of such outstanding shares of Common Stock is duly and validly authorized,
validly issued, fully paid, and nonassessable, has not been issued and is not
owned or held in violation of any preemptive or similar right of stockholders.
Each share of capital stock of each OncoVista Subsidiary is duly and validly
authorized, validly issued, fully paid, and nonassessable, has not been issued
and is not owned or held in violation of any preemptive or similar right of
stockholders. Except as set forth in the PPM, (i) there is no commitment, plan,
or arrangement to issue, and no outstanding option, warrant, or other right
calling for the issuance of, any share of capital stock of, or any security or
other instrument convertible into, exercisable for, or exchangeable for capital
stock of, OncoVista, and (ii) except as described in the PPM or Schedule
6.01(f), there is outstanding no security or other instrument convertible into
or exchangeable for capital stock of OncoVista. The description of OncoVista's
stock option, stock bonus and other stock plans or arrangements, and the options
or other rights granted and exercised thereunder, set forth in the PPM
accurately and fairly presents the information required to be shown with respect
to such plans, arrangements, options and rights under the Securities Act, the
Exchange Act, and the rules and regulations promulgated thereunder.  
 
14

--------------------------------------------------------------------------------

 
(g) Berman & Company P.A. examined the financial statements of OncoVista,
together with the related schedules and notes, for the year ended December 31,
2006 (the “Auditor”), included in the PPM, is an independent accountant within
the meaning of the Securities Act, the Exchange Act, and the rules and
regulations promulgated thereunder; and the audited consolidated financial
statements of OncoVista, together with the related schedules and notes, and the
unaudited consolidated financial information, included in the PPM, fairly
present and will fairly present the consolidated financial position and the
results of operations of OncoVista at the respective dates and for the
respective periods to which they apply; and all consolidated audited financial
statements of OncoVista, together with the related schedules and notes will
comply as to form in all material respects with applicable accounting
requirements and with the rules and regulations of the SEC with respect thereto
at the date of preparation thereof, have been and will be prepared in accordance
with generally accepted accounting principles consistently applied throughout
the periods involved except as may be otherwise stated therein (except as may be
indicated in the notes thereto or as permitted by the rules and regulations of
the SEC) and fairly present and will fairly present, subject in the case of the
unaudited consolidated financial statements, to customary year end audit
adjustments, the consolidated financial position of OncoVista as at the dates
thereof and the results of its operations and cash flows. The procedures
pursuant to which the aforementioned financial statements have been audited are
compliant with generally accepted auditing standards. Since June 30, 2007 (the
“Last OncoVista Financial Statement Date”):

(i) There has at no time been a material adverse change in the financial
condition, results of operations, businesses, properties, assets, liabilities,
or future prospects of the OncoVista and the OncoVista Subsidiaries taken as a
whole;

(ii) OncoVista has not authorized, declared, paid, or effected any dividend or
liquidating or other distribution in respect of its capital stock or any direct
or indirect redemption, purchase, or other acquisition of any stock of
OncoVista.
 
(iii) Except as set forth in Section 6.01(a)(i)(C), the operations and
businesses of OncoVista have been conducted in all respects only in the ordinary
course.
 
(h) Subsequent to the respective dates as of which information is given in the
PPM, there has not been (i) any material adverse change in the business,
prospects, financial condition or results of operations of OncoVista and the
OncoVista Subsidiaries taken as a whole, (ii) except as set forth in Section
6.01(a)(i)(C), any transaction committed to or consummated that is material to
OncoVista and the OncoVista Subsidiaries taken as a whole, (iii) any obligation,
direct or contingent, that is material to OncoVista and the OncoVista
Subsidiaries taken as a whole incurred by OncoVista or any OncoVista Subsidiary,
except such obligations as have been incurred in the ordinary course of
business, (iv) any change in the capital stock or outstanding indebtedness of
the OncoVista or any OncoVista Subsidiaries that is material to OncoVista and
the OncoVista Subsidiaries taken as a whole, (v) any dividend or distribution of
any kind declared, paid, or made on the capital stock of OncoVista or any
OncoVista Subsidiaries, or (vi) any loss or damage (whether or not insured) to
the property of OncoVista or any OncoVista Subsidiary which has a material
adverse effect on the business, prospects, condition (financial or otherwise),
or results of operations of OncoVista and the OncoVista Subsidiaries taken as a
whole.

15

--------------------------------------------------------------------------------

 
(i) Neither OncoVista, nor any OncoVista Subsidiary, owns any legal or equitable
interest in any real property. OncoVista and each OncoVista Subsidiary has good
title to all other properties and assets material thereto, used in its business
or owned by it (except real and other properties and assets as are held pursuant
to leases or licenses described in the PPM), free and clear of all liens,
mortgages, security interests, pledges, charges, and encumbrances.

(i)  All accounts and notes receivable reflected in the OncoVista balance sheet
as of June 30, 2007 (“Last OncoVista Balance Sheet”), or arising since the Last
OncoVista Financial Statement Date, have been collected, or are and will be good
and collectible, in each case at the aggregate recorded amounts thereof without
right of recourse, defense, deduction, return of goods, counterclaim, offset, or
set off on the part of the obligor, and, if not collected, can reasonably be
anticipated to be paid within 30 days of the date incurred.

(ii)  All inventory of raw materials and work in process of OncoVista is usable,
and all inventory of finished goods is good and marketable, on a normal basis in
the existing product lines of OncoVista. In no event do such inventories
represent more than a one-month supply measured by the volume of sales or use
for the year ended December 31, 2006. All inventory is merchantable and fit for
the particular purpose for which it is intended.

(iii)  All properties and assets owned by OncoVista are reflected on the Last
OncoVista Balance Sheet (except for acquisitions subsequent to the Last
OncoVista Balance Sheet and prior to the Effective Time). All real and other
tangible properties and assets owned by OncoVista or leased or licensed by
OncoVista from or to a third party are in good and usable condition (reasonable
wear and tear which is not such as to affect adversely the operation of the
business of OncoVista excepted).

(iv)  To the best of OncoVista’s knowledge, no real property leased or licensed
by OncoVista from or to a third party lies in an area which is, or will be,
subject to zoning, use, or building code restrictions which would prohibit, and,
to the best of OncoVista’s knowledge, no state of facts relating to the actions
or inaction of another person or entity or his or its ownership, leasing, or
licensing of any real or personal property exists or will exist which would
prevent, the continued effective ownership, leasing, or licensing of such real
property in the businesses in which OncoVista is now engaged or the businesses
in which it contemplates engaging.

(v)  The properties and assets owned by OncoVista (other than those leased or
licensed by OncoVista to a third party) or leased or licensed by OncoVista from
a third party constitute all such properties and assets which are necessary to
the business of OncoVista as presently conducted or as it contemplates
conducting.
 
16

--------------------------------------------------------------------------------

 
(j) Except as disclosed in Schedule 6.01(k), OncoVista does not have any
insurance; OncoVista has at no time been refused any insurance coverage sought
or applied for.

(k) (i) No labor disturbance by the employees of OncoVista or any OncoVista
Subsidairies exists or, to the best of OncoVista’s knowledge, is imminent.
OncoVista is not aware of any existing or imminent labor disturbance by the
employees of any principal suppliers or customers of OncoVista that might be
expected to result in any material adverse change in the business, prospects,
financial condition, or results of operations of OncoVista and the OncoVista
Subsidiaries taken as a whole. No collective bargaining agreement exists with
any of the employees of OncoVista or any OncoVista Subsidiary and, to the best
of OncoVista’s knowledge, no such agreement is imminent.

(ii)  Except as set forth in the PPM, OncoVista does not have, or contribute to,
and has never maintained or contributed to, any pension, profit-sharing, option,
other incentive plan, or any other type of Employee Benefit Plan (as defined in
Section 3(3) of ERISA) or Pension Plan (as defined in ERISA) and OncoVista does
not have any obligation to or customary arrangement with employees for bonuses,
incentive compensation, vacations, severance pay, sick pay, sick leave,
insurance, service award, relocation, disability, tuition refund, or other
benefits, whether oral or written.
 
(l) OncoVista owns or possesses the right to use all patents, patent rights,
inventions, trade secrets, know-how, trademarks, service marks, trade names,
logos, and copyrights described or referred to in the PPM as owned by or used by
it or that are necessary to conduct its respective businesses as described in
the PPM; neither OncoVista or any OncoVista Subsidiary has received any notice
of, or has knowledge of, any infringement of or conflict with asserted rights
thereof by others with respect to any patents, patent rights, inventions, trade
secrets, know-how, trademarks, service marks, trade names, logos, or copyrights
described or referred to in the PPM as owned by or used by it; and OncoVista has
not received any notice of, or has no knowledge of, any infringement of, or
conflict with, asserted rights of others with respect to any patents, patent
rights, inventions, trade secrets, know-how, trademarks, service marks, trade
names, logos, or copyrights described or referred to in the PPM as owned by or
used by it or which, individually or in the aggregate, in the event of an
unfavorable decision, ruling or finding, would have a material adverse effect on
the business, prospects, financial condition or results of operations of
OncoVista and the OncoVista Subsidiaries, taken as a whole.

17

--------------------------------------------------------------------------------

 
(m) OncoVista has been advised concerning the Investment Company Act of 1940, as
amended (the “Investment Company Act”), and the rules and regulations
thereunder, and has in the past conducted, and intends in the future, to conduct
its affairs in such a manner as to ensure that it is not and will not become an
“investment company” or a company “controlled” by an “investment company” within
the meaning of the Investment Company Act and such rules and regulations.

(n) (i) Neither OncoVista nor any OncoVista Subsidiary has, and no person or
entity acting on behalf or at the request thereof has, at any time during the
last five years (i) made any unlawful contribution to any candidate for foreign
office or failed to disclose fully any contribution in violation of law, or (ii)
made any payment to any federal or state governmental officer or official, or
other person charged with similar public or quasi-public duties, other than
payments required or permitted by the laws of the United States or any other
applicable jurisdiction.

(ii) OncoVista nor any director, officer, agent, employee, or other person
associated with, or acting on behalf of, OncoVista, has, directly or indirectly:
used any corporate funds for unlawful contributions, gifts, entertainment, or
other unlawful expenses relating to political activity; made any unlawful
payment to foreign or domestic government officials or employees or to foreign
or domestic political parties or campaigns from corporate funds; violated any
provision of the Foreign Corrupt Practices Act of 1977, as amended; or made any
bribe, rebate, payoff, influence payment, kickback, or other unlawful payment.
OncoVista's internal accounting controls and procedures are sufficient to cause
OncoVista to comply in all respects with the Foreign Corrupt Practices Act of
1977, as amended.

(iii) Neither OncoVista nor any OncoVista Subsidiary, nor any officer, director
or, to the best of OncoVista's knowledge, affiliate of OncoVista or any
OncoVista Subsidiary, has been, within the five years ending at the Effective
Time, a party to any bankruptcy petition against such person or against any
business of which such person was affiliated; convicted in a criminal proceeding
or subject to a pending criminal proceeding (excluding traffic violations and
other minor offenses); subject to any order, judgment or decree, not
subsequently reversed, suspended or vacated, of any court of competent
jurisdiction, permanently or temporarily enjoining, barring, suspending or
otherwise limiting their involvement in any type of business, securities or
banking activities; or found by a court of competent jurisdiction in a civil
action, by the SEC or the Commodity Futures Trading Commission to have violated
a federal or state securities or commodities law, and the judgment has not been
reversed, suspended or vacated.

(o) Neither OncoVista nor any OncoVista Subsidiary, and no person acting on
behalf thereof, has taken or will take, directly or indirectly, any action
designed to, or that might reasonably be expected to cause or result in,
stabilization in violation of law, or manipulation, of the price of the AVUG
Common Stock.

18

--------------------------------------------------------------------------------

 
(p) Except as set forth in the PPM, (i) OncoVista and each OncoVista Subsidiary
is in compliance in all material respects with all rules, laws and regulations
relating to the use, treatment, storage and disposal of toxic substances and
protection of health or the environment (“Environmental Laws”) that are
applicable to its business, (ii) neither OncoVista nor any OncoVista Subsidiary
has received notice from any governmental authority or third party of an
asserted claim under Environmental Laws, (iii) to the best knowledge of
OncoVista, neither OncoVista nor any OncoVista Subsidiary is likely to be
required to make future material capital expenditures to comply with
Environmental Laws, except in the ordinary course of its respective business,
(iv) no property which is owned, leased or occupied by OncoVista or any
OncoVista Subsidiary has been designated as a Superfund site pursuant to the
Comprehensive Response, Compensation, and Liability Act of 1980, as amended (42
U.S.C. § 9601, et seq.), or otherwise designated as a contaminated site under
applicable state or local law, and (v) OncoVista is not in violation of any
federal or state law or regulation relating to occupational safety or health.
 
(q) There are no outstanding loans, advances or guarantees of indebtedness by
OncoVista to, or for the benefit of, any of the officers, directors, or
director-nominees of OncoVista or any of the members of the families of any of
them, except as disclosed in the PPM.

(r) Neither OncoVista nor any OncoVista Subsidiary has incurred any liability,
direct or indirect, for finders' or similar fees on behalf of or payable by
OncoVista or AVUG in connection with the Merger, except as otherwise disclosed
herein or paid by OncoVista prior to the date hereof.
 
(s) To its best knowledge, OncoVista believes that it is in compliance with, and
is not in violation of, applicable federal, state, local or foreign statutes,
laws and regulations (including without limitation, any applicable building,
zoning or other law, ordinance or regulation) affecting its properties or the
operation of its business, including, without limitation, Sarbanes-Oxley Act of
2002 and the rules and regulations promulgated pursuant thereto or thereunder.
OncoVista is not subject to any order, decree, judgment or other sanction of any
court, administrative agency or other tribunal.

19

--------------------------------------------------------------------------------

 
(t) Schedule 6.01(v) contains a true, correct, and complete description of the
material contracts, agreements, instruments, leases, licenses, arrangements, or
understandings with respect to OncoVista and the OncoVista Subsidiaries.
OncoVista has made available to AVUG (i) the certificate of incorporation (or
other charter document) and by-laws of OncoVista and all amendments thereto, as
presently in effect, certified by the Secretary of such corporation and (ii) the
following: (A) true and correct copies of all material contracts, agreements,
and instruments referred to in Schedule 6.01(t); (B) true and correct copies of
all material leases and licenses referred to in Schedule 6.01(v); and (C) true
and correct written descriptions of all material supply, distribution, agency,
financing, or other arrangements or understandings referred to in Schedule
6.01(v). To the best of OncoVista’s knowledge, none of OncoVista or any other
party to any such contract, agreement, instrument, lease, or license is now or
expects in the future to be in violation or breach of, or in default with
respect to complying with, any term thereof, and each such material contract,
agreement, instrument, lease, or license is in full force and is (to the best of
OncoVista’s knowledge in the case of third parties) the legal, valid, and
binding obligation of the parties thereto and (subject to applicable bankruptcy,
insolvency, and other laws affecting the enforceability of creditors’ rights
generally) is enforceable as to them in accordance with its terms. Each such
material supply, distribution, agency, financing, or other arrangement or
understanding is a valid and continuing arrangement or understanding; none of
OncoVista or any other party to any such arrangement or understanding has given
notice of termination or taken any action inconsistent with the continuance of
such arrangement or understanding; and the execution, delivery, and performance
of this Agreement will not prejudice any such arrangement or understanding in
any way. OncoVista enjoys peaceful and undisturbed possession under all leases
and licenses under which it is operating. OncoVista is not party to or bound by
any contract, agreement, instrument, lease, license, arrangement, or
understanding, or subject to any charter or other restriction, which has had or,
to the best of OncoVista’s knowledge, may in the future have a material adverse
effect on the business, prospects, financial condition, or results of operations
of OncoVista and the Surviving Corporation. OncoVista has not engaged within the
last five years in, is engaging in, or intends to engage in any transaction
with, or has had within the last five years, now has, or intends to have any
contract, agreement, instrument, lease, license, arrangement, or understanding
with, any stockholder of OncoVista, any director, officer, or employee of
OncoVista, any relative or affiliate of any stockholder of OncoVista, any such
director, officer, or employee, or any other corporation or enterprise in which
any stockholder of OncoVista, any such director, officer, or employee, or any
such relative or affiliate then had or now has a 5% or greater equity or voting
or other substantial interest, other than those described in the PPM and
Schedule 6.01(t). The stock ledgers and stock transfer books and the minute book
records of OncoVista relating to all issuances and transfers of stock by
OncoVista and all proceedings of the stockholders and the Board of Directors and
committees thereof of OncoVista since their respective incorporations made
available to AVUG are the original stock ledgers and stock transfer books and
minute book records of OncoVista or exact copies thereof. OncoVista is not in
violation or breach of, or in default with respect to, any term of its
certificate of incorporation (or other charter document) or by-laws.

(u) No representation or warranty by OncoVista in this Agreement contains, or at
the Effective Time will contain, an untrue statement of material fact or omits
or at the Effective Time will omit to state a material fact required to be
stated therein or necessary to make the statements made not misleading.
Notwithstanding the foregoing, such representations and warranties by OncoVista
shall be deemed to comply with, and not be in breach or contravention of, or in
default with respect to the immediately preceding sentence to the extent that
such representations and warranties shall at the Effective Time be untrue in any
material respect or omit to state a material fact required to be stated therein
or necessary to make the statements therein not misleading as a result of any
transaction contemplated hereby or in connection herewith.
 
Section 6.02 Certain Representations and Warranties of AVUG and Acquisition.  

Except as set forth in any SEC Document (as defined below), AVUG and Acquisition
each represents and warrants to OncoVista as follows:

20

--------------------------------------------------------------------------------

 
(a) (i) The AVUG Common Stock has been registered under Section 12(g) of the
Exchange Act and AVUG is subject to the periodic reporting requirements of
Section 13 of the Exchange Act. AVUG has made available to OncoVista true,
complete, and correct copies of all forms, reports, schedules, statements, and
other documents required to be filed by it under the Exchange Act, as such
documents have been amended since the time of the filing thereof (collectively,
including all forms, reports, schedules, statements, exhibits, and other
documents filed by AVUG therewith, the “SEC Documents”). The SEC Documents,
including, without limitation, any financial statements and schedules included
therein, at the time filed or, if subsequently amended, as so amended, (i) did
not contain any untrue statement of a material fact required to be stated
therein or necessary in order to make the statements therein not misleading and
(ii) complied in all respects with the applicable requirements of the Exchange
Act and the applicable rules and regulations thereunder. To AVUG’s knowledge,
each director and executive officer thereof has filed with the SEC on a timely
basis all statements required by Section 16(a) of the Exchange Act and the rules
and regulations thereunder.

(ii) AVUG maintains disclosure controls and procedures required by Rule 13a-15
or 15d-15 under the Exchange Act; such controls and procedures are effective to
ensure that:

(A) all material information concerning AVUG is made known on a timely basis to
the individuals responsible for the preparation of AVUG’s filings with the SEC
and other public disclosure documents;

(B) transactions are executed in accordance with management’s general or
specific authorizations;

(C) transactions are recorded as necessary to permit preparation of financial
statements in accordance with generally accepted accounting principles and to
maintain asset accountability;

(D) access to assets is permitted only in accordance with management’s general
or specific authorization; and

(E)  the recorded accountability for assets is compared with the existing assets
at reasonable intervals and appropriate action is taken with respect to any
differences.

AVUG has made available to OncoVista copies of, all written descriptions of, and
all policies, manuals and other documents promulgating, such disclosure controls
and procedures.  The books, records and accounts of AVUG accurately and fairly
reflect, in reasonable detail, the transactions in, and dispositions of, the
assets of, and the results of operations of, AVUG all to the extent required by
generally accepted accounting principles.

(iii) The Chief Executive Officer and the Chief Financial Officer of AVUG have
signed, and AVUG has furnished to the SEC, all certifications required by
Sections 302 and 906 of the Sarbanes-Oxley Act of 2002; such certifications
contain no qualifications or exceptions to the matters certified therein and
have not been modified or withdrawn (except as permitted by applicable laws or
regulations); and neither AVUG nor any of its officers has received notice from
any governmental entity questioning or challenging the accuracy, completeness,
form or manner of filing or submission of such certifications.

21

--------------------------------------------------------------------------------

 
(iv) AVUG has heretofore provided to OncoVista complete and correct copies of
all certifications filed with the SEC pursuant to Sections 302 and 906 of
Sarbanes-Oxley Act of 2002 and hereby reaffirms, represents and warrants to
OncoVista the matters and statements made in such certificates.

(b) At the date hereof and at the Effective Time:

(i)  the AVUG Common Stock is eligible to trade and be quoted on, and is quoted
on, the over-the-counter Bulletin Board market maintained by The Nasdaq Stock
Market (the “OTCBB”) and has received no notice or other communication
indicating that such eligibility is subject to challenge or review by the any
applicable regulatory agency, electronic market administrator, or exchange;

(ii)  AVUG has and shall have performed or satisfied all of its undertakings to,
and of its obligations and requirements with, the SEC; and

(iii)  AVUG has not, and shall not have taken any action that would preclude, or
otherwise jeopardize, the inclusion of the AVUG Common Stock for quotation on
the OTCBB.

(c) Other than Acquisition at the Effective Time, AVUG has no subsidiaries or
affiliated corporation or owns any interest in any other enterprise (whether or
not such enterprise is a corporation). Each of AVUG and Acquisition has been
duly organized and is validly existing as a corporation in good standing under
the laws of its respective jurisdiction of incorporation with full power and
authority (corporate and other) to own, lease and operate its respective
properties and conduct its respective business as described in the SEC
Documents; except as otherwise disclosed on Schedule 6.02(c), AVUG is duly
qualified to do business as a foreign corporation and is in good standing in
each jurisdiction in which the ownership or leasing of its properties or the
conduct of its business requires such qualification, except where the failure to
be so qualified or be in good standing would not have a material adverse effect
on its business, prospects, condition (financial or otherwise), and results of
operations of AVUG; no proceeding has been instituted in any such jurisdiction,
revoking, limiting or curtailing, or seeking to revoke, limit or curtail, such
power and authority or qualification; AVUG is in possession of, and operating in
compliance with, all authorizations, licenses, certificates, consents, orders
and permits from state, federal, foreign and other regulatory authorities that
are material to the conduct of its business, all of which are valid and in full
force and effect; AVUG is not in violation of its charter or bylaws or in
default in the performance or observance of any obligation, agreement, covenant
or condition contained in any material bond, debenture, note or other evidence
of indebtedness, or in any material lease, contract, indenture, mortgage, deed
of trust, loan agreement, joint venture or other agreement or instrument to
which it is a party or by which it or its properties or assets may be bound,
which violation or default would have a material adverse effect on the business,
prospects, financial condition or results of operations of AVUG; and AVUG is not
in violation of any law, order, rule, regulation, writ, injunction, judgment or
decree of any court, government or governmental agency or body, domestic or
foreign, having jurisdiction over AVUG or over its properties or assets, which
violation would have a material adverse effect on the business, prospects,
financial condition or results of operations of AVUG taken as a whole. The SEC
Documents accurately describe any corporation, association or other entity owned
or controlled, directly or indirectly, by AVUG.

22

--------------------------------------------------------------------------------

 
(d) Each of AVUG and Acquisition has all requisite power and authority to
execute, deliver, and perform this Agreement. Except as set forth in this
Agreement, all necessary proceedings of each of AVUG and Acquisition have been
duly taken to authorize the execution, delivery, and performance of this
Agreement thereby. This Agreement has been duly authorized, executed, and
delivered by AVUG and Acquisition, constitutes the legal, valid, and binding
obligation of each of AVUG and Acquisition, and is enforceable as to AVUG and
Acquisition in accordance with its terms. Except as otherwise set forth in this
Agreement, no consent, authorization, approval, order, license, certificate, or
permit of or from, or declaration or filing with, any federal, state, local, or
other governmental authority or any court or other tribunal is required by the
AVUG or Acquisition for the execution, delivery, or performance of this
Agreement thereby. No consent, approval, authorization or order of, or
qualification with, any court, government or governmental agency or body,
domestic or foreign, having jurisdiction over AVUG or Acquisition or over its
respective properties or assets is required for the execution and delivery of
this Agreement and the consummation by AVUG of the transactions herein and
therein contemplated, except such as may be required under the Securities Act or
under state or other securities or blue sky laws, all of which requirements have
been, or in accordance therewith will be, satisfied in all material respects. No
consent of any party to any material contract, agreement, instrument, lease,
license, arrangement, or understanding to which the AVUG or Acquisition is a
party, or to which its or any of its respective businesses, properties, or
assets are subject, is required for the execution, delivery, or performance of
this Agreement; and the execution, delivery, and performance of this Agreement
will not violate, result in a breach of, conflict with, or (with or without the
giving of notice or the passage of time or both) entitle any party to terminate
or call a default under, entitle any party to receive rights or privileges that
such party was not entitled to receive immediately before this Agreement was
executed under, or create any obligation on the part of AVUG or Acquisition to
which it was not subject immediately before this Agreement was executed under,
any term of any such material contract, agreement, instrument, lease, license,
arrangement, or understanding, or violate or result in a breach of any term of
the respective certificate of incorporation or respective by-laws of AVUG or
Acquisition (if the provisions of this Agreement are satisfied) violate, result
in a breach of, or conflict with any law, rule, regulation, order, judgment,
decree, injunction, or writ of any court, government or governmental agency or
body, domestic or foreign, having jurisdiction over AVUG or Acquisition or over
its respective properties or assets.

(e) There is not any pending or, to the best of AVUG's or Acqusition’s
knowledge, threatened, action, suit, claim or proceeding against AVUG or
Acquisition, or any of AVUG’s or Acquisition’s officers or any of the respective
properties, assets or rights of AVUG or Acquisition, before any court,
government or governmental agency or body, domestic or foreign, having
jurisdiction over AVUG or Acquisition or over AVUG’s or Acquisition’s respective
officers or the respective properties of AVUG or Acquisition, or otherwise that
(i) is reasonably likely to result in any material adverse change in the
respective business, prospects, financial condition or results of operations of
AVUG or Acquisition or might materially and adversely affect their properties,
assets or rights taken as a whole, (ii) might prevent consummation of the
transactions contemplated by this Agreement, or (iii) alleging violation of any
Federal or state securities laws.
 
23

--------------------------------------------------------------------------------

(f) After giving effect of the Stock Split, the authorized capital stock of AVUG
consists of 147,397,390 shares of AVUG Common Stock, of which 16,888,475 shares
of AVUG Common Stock are outstanding. Each of such outstanding shares of AVUG
Common Stock is duly and validly authorized, validly issued, fully paid, and
nonassessable, has not been issued and is not owned or held in violation of any
preemptive or similar right of stockholders. The authorized capital stock of
Acquisition consists of 1,000 shares of common stock, par value $0.001 per
share, of which ten shares are outstanding. Each of such outstanding shares of
AVUG Common Stock and Acquisition Capital Stock is duly and validly authorized,
validly issued, fully paid, and nonassessable, has not been issued and is not
owned or held in violation of any preemptive or similar right of stockholders.
There is no commitment, plan, or arrangement to issue, and no outstanding
option, warrant, or other right calling for the issuance of, any share of
capital stock of, or any security or other instrument convertible into,
exercisable for, or exchangeable for capital stock of, AVUG or Acquisition, and
there is outstanding no security or other instrument convertible into or
exchangeable for capital stock of AVUG or Acquisition. The description of AVUG's
stock option, stock bonus and other stock plans or arrangements, and the options
or other rights granted and exercised thereunder, set forth in the SEC Documents
accurately and fairly presents the information required to be shown with respect
to such plans, arrangements, options and rights under the Securities Act, the
Exchange Act, and the rules and regulations promulgated thereunder. There are no
options or warrants or convertible or exchangeable securities of AVUG or
Acquisition outstanding at the date hereof.

(g) Stan J.H. Lee, CPA examined the financial statements of AVUG, together with
the related schedules and notes, for the period from January 1, 2006 through
December 31, 2006, and Armando C. Ibarra, CPA examined the financial statements
of AVUG, together with the related schedules and notes, for the period from
January 1, 2005 through December 31, 2005 (collectively, the “Auditors”), filed
with the SEC as a part of the SEC Documents, are independent accountants within
the meaning of the Securities Act, the Exchange Act, and the rules and
regulations promulgated thereunder; and except as disclosed in Schedule 6.02(g),
the audited financial statements of AVUG, together with the related schedules
and notes, and the unaudited financial information, forming part of the SEC
Documents, fairly present and will fairly present the financial position and the
results of operations of AVUG at the respective dates and for the respective
periods to which they apply; and all audited financial statements of AVUG,
together with the related schedules and notes, and the unaudited financial
information, filed with the SEC as part of the SEC Documents, complied and will
comply as to form in all material respects with applicable accounting
requirements and with the rules and regulations of the SEC with respect hereto
when filed, have been and will be prepared in accordance with generally accepted
accounting principles consistently applied throughout the periods involved
except as may be otherwise stated therein (except as may be indicated in the
notes thereto or as permitted by the rules and regulations of the SEC) and
fairly present and will fairly present, subject in the case of the unaudited
financial statements, to customary year end audit adjustments, the financial
position of AVUG as at the dates thereof and the results of its operations and
cash flows. The procedures pursuant to which the aforementioned financial
statements have been audited are compliant with generally accepted auditing
standards. The selected and summary financial and statistical data included in
the SEC Documents present and will present fairly the information shown therein
and have been compiled on a basis consistent with the audited financial
statements presented therein. No other financial statements or schedules are
required to be included in the SEC Documents. The financial statements referred
to in this Section 6.02 (g) contain all certifications and statements required
under the SEC’s Order, dated June 27, 2002, pursuant to Section 21(a)(1) of the
Exchange Act (File No. 4-460), Rule 13a-14 or 15d-14 under the Exchange Act, or
18 U.S.C. Section 1350 (Sections 302 and 906 of the Sarbanes-Oxley Act of 2002)
with respect to the report relating thereto. Acquisition has no assets or
liabilities. Since June 30, 2007 ("Last AVUG Financial Statement Date"):

24

--------------------------------------------------------------------------------

 
(i) There has at no time been a material adverse change in the financial
condition, results of operations, businesses, properties, assets, liabilities,
or future prospects of AVUG or Acquisition;

(ii) Neither AVUG nor Acquisition has authorized, declared, paid, or effected
any dividend or liquidating or other distribution in respect of its capital
stock or any direct or indirect redemption, purchase, or other acquisition of
any stock of AVUG or Acquisition.
 
(iii) The operations and businesses of AVUG have been conducted in all respects
only in the ordinary course.  There is no fact known to AVUG or Acquisition
which materially adversely affects or in the future (as far as AVUG or
Acquisition can reasonably foresee) may materially adversely affect the
financial condition, results of operations, businesses, properties, assets,
liabilities, or future prospects of AVUG and Acquisition, and, after the Merger,
the Surviving Corporation; provided, however, that neither AVUG nor Acquisition
expresses any opinion as to political or economic matters of general
applicability. AVUG has made known, or caused to be made known, to the
accountants or auditors who have prepared, reviewed, or audited the
aforementioned consolidated financial statements all material facts and
circumstances which could affect the preparation, presentation, accuracy, or
completeness thereof.

(h) Subsequent to the respective dates as of which information is given in the
SEC Documents, there has not been (i) any material adverse change in the
consolidated business, prospects, financial condition or results of operations
of AVUG, (ii) any transaction committed to or consummated that is material to
AVUG and Acquisition taken as a whole, (iii) any obligation, direct or
contingent, that is material to AVUG and Acquisition taken as a whole incurred
by AVUG or Acquisition, (iv) any change in the capital stock or outstanding
indebtedness of AVUG or Acquisition that is material to AVUG and Acquisition
taken as a whole, (v) any dividend or distribution of any kind declared, paid,
or made on the capital stock of AVUG or Acquisition, or (vi) any loss or damage
(whether or not insured) to the property of AVUG or Acquisition which has a
material adverse effect on the business, prospects, condition (financial or
otherwise), or results of operations thereof, in each case, taken as a whole.

(i) At the Effective Time, neither AVUG nor Acquisition shall have any
properties or assets and each of AVUG and Acquisition shall be free and clear of
any pledge, lien, security interest, encumbrance, claim or equitable interest.
At the Effective Time, neither AVUG nor Acquisition shall be party to any
agreements except for this Agreement and the Securities Purchase Agreement dated
as of August 16, 2007 among OncoVista, AVUG and Torbjorn Lundqvist, which shall
be legal, valid and binding agreements, enforceable against each of AVUG and
Acquisition in accordance with its terms.

25

--------------------------------------------------------------------------------

 
(j) Neither AVUG nor Acquisition has any liability of any nature, accrued or
contingent, including, without limitation, liabilities for federal, state,
local, or foreign taxes and penalties, interest, and additions to tax (“Taxes”),
and liabilities to customers or suppliers. Without limiting the generality of
the foregoing, the amounts set up as provisions for Taxes, if any, in the last
AVUG financial statements are sufficient for all accrued and unpaid Taxes of
AVUG, whether or not due and payable and whether or not disputed, under tax
laws, as in effect on the Last AVUG Financial Statement Date or now in effect,
for the period ended on such date and for all fiscal periods prior thereto. The
execution, delivery, and performance of this Agreement by each of AVUG and
Acquisition will not cause any Taxes to be payable or cause any lien, charge, or
encumbrance to secure any Taxes to be created either immediately or upon the
nonpayment of any Taxes. The Internal Revenue Service has audited and settled or
the statute of limitations has run upon all federal income tax returns of AVUG
for all taxable years up to and including the taxable year ended December 31,
2000. AVUG has filed all federal, state, local, and foreign tax returns required
to be filed by it; has made available to OncoVista a true and correct copy of
each such return which was filed in the past six years; has paid (or has
established on the last balance sheet included in the last AVUG financial
statement a reserve for) all Taxes, assessments, and other governmental charges
payable or remittable by it or levied upon it or its properties, assets, income,
or franchises which are due and payable; and has delivered to OncoVista a true
and correct copy of any report as to adjustments received by it from any taxing
authority during the past six years and a statement as to any litigation,
governmental or other proceeding (formal or informal), or investigation pending,
threatened, or in prospect with respect to any such report or the subject matter
of such report. AVUG has paid all taxes payable thereby due on or prior to the
date hereof.

(k) Neither AVUG nor Acquisition has any insurance; neither AVUG nor Acquisition
has at any time been refused any insurance coverage sought or applied for.

(l) (i) No labor disturbance by the employees of AVUG exists or, to the best of
AVUG’s knowledge, is imminent. AVUG is not aware of any existing or imminent
labor disturbance by the employees of any principal suppliers or customers of
AVUG that might be expected to result in any material adverse change in the
business, prospects, financial condition, or results of operations of AVUG. No
collective bargaining agreement exists with any of AVUG’s employees and, to the
best of AVUG's knowledge, no such agreement is imminent.

(ii) AVUG does not have, or contribute to, and has never maintained or
contributed to, any pension, profit-sharing, option, other incentive plan, or
any other type of Employee Benefit Plan (as defined in Section 3(3) of ERISA) or
Pension Plan (as defined in ERISA) and AVUG does not have any obligation to or
customary arrangement with employees for bonuses, incentive compensation,
vacations, severance pay, sick pay, sick leave, insurance, service award,
relocation, disability, tuition refund, or other benefits, whether oral or
written.
 
(m) AVUG does not own or possess the right to use any patents, patent rights,
inventions, trade secrets, know-how, trademarks, service marks, trade names,
logos, or copyrights; AVUG has not received any notice of, or has knowledge of,
any infringement of or conflict with asserted rights of AVUG by others with
respect to any patents, patent rights, inventions, trade secrets, know-how,
trademarks, service marks, trade names, logos, or copyrights described or
referred to in the SEC Documents as owned by or used by it; and AVUG has not
received any notice of, or has no knowledge of, any infringement of, or conflict
with, asserted rights of others with respect to any patents, patent rights,
inventions, trade secrets, know-how, trademarks, service marks, trade names,
logos, or copyrights described or referred to in the SEC Documents as owned by
or used by it or which, individually or in the aggregate, in the event of an
unfavorable decision, ruling or finding, would have a material adverse effect on
the business, prospects, financial condition or results of operations of AVUG.

(n) AVUG has been advised concerning the Investment Company Act of 1940, as
amended (the “Investment Company Act”), and the rules and regulations
thereunder, and has in the past conducted, and intends in the future, to conduct
its affairs in such a manner as to ensure that it is not and will not become an
“investment company” or a company “controlled” by an “investment company” within
the meaning of the Investment Company Act and such rules and regulations.

26

--------------------------------------------------------------------------------

(o) (i) AVUG has not, and no person or entity acting on behalf or at the request
of AVUG has, at any time during the last five years (i) made any unlawful
contribution to any candidate for foreign office or failed to disclose fully any
contribution in violation of law, or (ii) made any payment to any federal or
state governmental officer or official, or other person charged with similar
public or quasi-public duties, other than payments required or permitted by the
laws of the United States or any other applicable jurisdiction.

(ii) Neither AVUG, nor, to the best knowledge of AVUG, any director, officer,
agent, employee, or other person associated with, or acting on behalf of, AVUG,
has, directly or indirectly: used any corporate funds for unlawful
contributions, gifts, entertainment, or other unlawful expenses relating to
political activity; made any unlawful payment to foreign or domestic government
officials or employees or to foreign or domestic political parties or campaigns
from corporate funds; violated any provision of the Foreign Corrupt Practices
Act of 1977, as amended; or made any bribe, rebate, payoff, influence payment,
kickback, or other unlawful payment.  AVUG’s internal accounting controls and
procedures are sufficient to cause AVUG to comply in all respects with the
Foreign Corrupt Practices Act of 1977, as amended.

(iii) Neither AVUG, nor any officer, director or affiliate of AVUG, has been,
within the five years ending on the Effective Time, a party to any bankruptcy
petition against such person or against any business of which such person was
affiliated; convicted in a criminal proceeding or subject to a pending criminal
proceeding (excluding traffic violations and other minor offenses); subject to
any order, judgment or decree, not subsequently reversed, suspended or vacated,
of any court of competent jurisdiction, permanently or temporarily enjoining,
barring, suspending or otherwise limiting their involvement in any type of
business, securities or banking activities; or found by a court of competent
jurisdiction in a civil action, by the SEC or the Commodity Futures Trading
Commission to have violated a federal or state securities or commodities law,
and the judgment has not been reversed, suspended or vacated.

(p) AVUG has not, and no person acting on behalf thereof, has taken or will
take, directly or indirectly, any action designed to, or that might reasonably
be expected to cause or result in, stabilization in violation of law, or
manipulation, of the price of the AVUG Common Stock.

(q) AVUG is in compliance in all material respects with all rules, laws and
regulations relating to the use, treatment, storage and disposal of toxic
substances and protection of health or the environment (“Environmental Laws”)
that are applicable to its business. AVUG has not received notice from any
governmental authority or third party of an asserted claim under Environmental
Laws, which claim is required to be disclosed in the SEC Documents. To the best
knowledge of AVUG, AVUG is not likely to be required to make future material
capital expenditures to comply with Environmental Laws. No property which is
owned, leased or occupied by AVUG has been designated as a Superfund site
pursuant to the Comprehensive Response, Compensation, and Liability Act of 1980,
as amended (42 U.S.C. § 9601, et seq.), or otherwise designated as a
contaminated site under applicable state or local law. AVUG is not in violation
of any federal or state law or regulation relating to occupational safety or
health.
 
27

--------------------------------------------------------------------------------

 
(r) There are no outstanding loans, advances or guarantees of indebtedness by
AVUG to, or for the benefit of, any of the officers, directors, or
director-nominees of AVUG or any of the members of the families of any of them.

(s) AVUG has not incurred any liability, direct or indirect, for finders' or
similar fees on behalf of or payable by AVUG or OncoVista in connection with
this Agreement.
 
(t) No stockholder of AVUG has any right to request or require AVUG to register
the sale of any shares owned by such stockholder under the Securities Act on any
registration statement.
 
(u) AVUG is in compliance with, and is not in violation of, applicable federal,
state, local or foreign statutes, laws and regulations (including without
limitation, any applicable building, zoning or other law, ordinance or
regulation) affecting its properties or the operation of its business,
including, without limitation, Sarbanes-Oxley Act of 2002 and the rules and
regulations promulgated pursuant thereto or thereunder. AVUG is not subject to
any order, decree, judgment or other sanction of any court, administrative
agency or other tribunal.

(v) AVUG has made available to OncoVista the certificate of incorporation (or
other charter document) and by-laws of each of AVUG and Acquisition and all
amendments thereto, as presently in effect, certified by the Secretary of such
corporation. The stock ledgers and stock transfer books and the minute book
records of OncoVista relating to all issuances and transfers of stock by AVUG
and Acquisition and all proceedings of the stockholders and the Board of
Directors and committees thereof of AVUG and Acquisition since their respective
incorporations made available to OncoVista are the original stock ledgers and
stock transfer books and minute book records of AVUG or Acquisition, as
applicable, or exact copies thereof. Neither AVUG nor Acquisition is in
violation or breach of, or in default with respect to, any term of its
respective certificate of incorporation (or other charter document) by-laws.
 
28

--------------------------------------------------------------------------------

 
(w) Assuming without investigation that the shares of OncoVista Common Stock at
the Effective Time will be validly authorized, validly issued, fully paid, and
nonassessable, the shares of AVUG Common Stock to be issued in the Merger are
validly authorized and, when the Merger has become effective and the shares of
AVUG Common Stock have been duly delivered pursuant to the terms of this
Agreement, such shares of AVUG Common Stock will be validly issued, fully paid,
and nonassessable.

(x) (i)  Neither AVUG nor Acquisition has taken or agreed to take any action
(other than actions contemplated by this Agreement) that could reasonably be
expected to prevent the Merger from constituting a “reorganization” under
section 368(a) of the Code. AVUG is not aware of any agreement, plan or other
circumstance that could reasonably be expected to prevent the Merger from so
qualifying.

(ii)  AVUG has no plan or intention to liquidate Surviving Corporation following
the merger or close Surviving Corporation to sell or otherwise dispose of any
assets of OncoVista acquired in the merger, except for dispositions made in the
ordinary course of business or transfers described in section 368(a)(2)(C) of
the Code and the Treasury Regulations issued thereunder.

(iii)  AVUG has no plan or intention to reacquire, and, to AVUG’s knowledge, no
person related to AVUG within the meaning of Treasury Regulations Section
1.368-1. has a plan or intention to acquire, any of the AVUG Common Stock issued
in the Merger.

(y) No representation or warranty by AVUG or Acquisition in this Agreement
contains, or at the Effective Time, will contain an untrue statement of material
fact or omits or at the Effective Time will omit to state a material fact
required to be stated therein or necessary to make the statements made not
misleading. Notwithstanding the foregoing, such representations and warranties
by AVUG and Acquisition shall be deemed to comply with, and not be in breach or
contravention of, or in default with respect to the immediately preceding
sentence to the extent that such representations and warranties shall at the
Effective Time be untrue in any material respect or omit to state a material
fact required to be stated therein or necessary to make the statements therein
not misleading as a result of any transaction contemplated hereby or in
connection herewith.

VII. CONDITIONS; ABANDONMENT AND TERMINATION

Section 7.01 Right of AVUG and Acquisition to Abandon. AVUG’s and Acquisition’s
Boards of Directors shall have the right to abandon or terminate the Merger if
any of the following conditions shall not be true or shall not have occurred, as
the case may be, as of the specified date or dates:

(a) Subject to Section 6.01(v) hereof, all representations and warranties of
OncoVista contained in this Agreement shall be accurate when made and, in
addition, shall be accurate as of the Effective Time as though such
representations and warranties were then made in exactly the same language by
OncoVista and regardless of knowledge or lack thereof on the part of OncoVista
or changes beyond its control; as of the Effective Time OncoVista shall have
performed and complied with all covenants and agreements and satisfied all
conditions required to be performed and complied with by it at or before the
Effective Time, respectively, by this Agreement; and AVUG and Acquisition shall
have received a certificate executed by the chief executive officer and the
chief financial officer of OncoVista, dated the Effective Time, to that effect.
 
29

--------------------------------------------------------------------------------

 
(b) AVUG and Acquisition shall have received at the Effective Time certificates
executed by the chief executive officer and the chief financial officer of
OncoVista as of such dates, to the effect that they have carefully examined the
Periodic Reports, and any amendment or supplement thereto, and, to the best of
their knowledge, (i) neither the Periodic Reports, nor any amendment or
supplement thereto (A) contains an untrue statement of a material fact or (B)
omits to state a material fact required to be stated therein or necessary to
make the statements therein not false or misleading, provided in each case that
such untrue statement or omission relates to information furnished by or on
behalf of, or pertaining to, OncoVista or any OncoVista security holder, (ii)
since the date hereof, no event with respect to OncoVista or any OncoVista
security holder has occurred which should have been set forth in an amendment to
any Periodic Report, or a supplement to any Periodic Report which has not been
set forth in such an amendment or supplement, and (iii) any contract, agreement,
instrument, lease, or license regarding OncoVista required to be filed as an
exhibit to any Periodic Report has been filed with the SEC as an exhibit to or
has been incorporated as an exhibit by reference into such Periodic Report.

(c) OncoVista shall have delivered to AVUG and Acquisition at or prior to the
Effective Time such other documents (including certificates of officers of
OncoVista) as AVUG may reasonably request in order to enable AVUG and
Acquisition to determine whether the conditions to their obligations under this
Agreement have been met and otherwise to carry out the provisions of this
Agreement.

(d) All actions, proceedings, instruments, and documents required by OncoVista
to carry out this Agreement or incidental thereto and all other related legal
matters shall be subject to the reasonable approval of AVUG and Acquisition, and
OncoVista shall have furnished AVUG and Acquisition such documents as such
counsel may have reasonably requested for the purpose of enabling them to pass
upon such matters.

(e) At the Effective Time, there shall not be pending any legal proceeding
relating to, or seeking to prohibit or otherwise challenge the consummation of,
the transactions contemplated by this Agreement, or to obtain substantial
damages with respect thereto.
 
(f) There shall not have been any action taken, or any law, rule, regulation,
order, judgment, or decree proposed, promulgated, enacted, entered, enforced, or
deemed applicable to the transactions contemplated by this Agreement by any
federal, state, local, or other governmental authority or by any court or other
tribunal, including the entry of a preliminary or permanent injunction, which,
in the reasonable judgment of AVUG, (i) makes this Agreement, the Merger, or any
of the other transactions contemplated by this Agreement illegal, (ii) results
in a delay in the ability of OncoVista, AVUG, or Acquisition to consummate the
Merger or any of the other transactions contemplated by this Agreement beyond
December 31, 2007, (iii) requires the divestiture by AVUG of a material portion
of the business of either AVUG and Acquisition taken as a whole, or of
OncoVista, (iv) imposes material limitations on the ability of AVUG effectively
to exercise full rights of ownership of shares of the Surviving Corporation
including the right to vote such shares on all matters properly presented to the
stockholders of the Surviving Corporation, or (v) otherwise prohibits,
restricts, or delays consummation of the Merger or any of the other transactions
contemplated by this Agreement or impairs the contemplated benefits to AVUG or
Acquisition of this Agreement, the Merger, or any of the other transactions
contemplated by this Agreement.
 
30

--------------------------------------------------------------------------------

 
(g) If required thereby, the OTC Bulletin Board shall, at or prior to the
Effective Time, have approved the inclusion thereon of the AVUG Common Stock to
be issued in the Merger.

(h) The parties to this Agreement shall have obtained at or prior to the
Effective Time all unconditional written approval to this Agreement and to the
execution, delivery, and performance of this Agreement by each of them of
relevant governmental authorities having jurisdiction over AVUG, Acquisition, or
OncoVista or the subject matter of this Agreement.

(i) The parties to this Agreement shall have obtained at or prior to the
Effective Time all consents required for the consummation of the Merger and the
other transactions contemplated by this Agreement from any unrelated third party
to any contract, agreement, instrument, lease, license, arrangement, or
understanding to which any of them is a party, or to which any of them or any of
their respective businesses, properties, or assets are subject.

(j) There shall not have been any material adverse change in the condition
(financial or otherwise), operations, business, assets, liabilities, earnings or
prospects of OncoVista since the date hereof.

(k) AVUG and Acquisition shall conduct a due diligence review of OncoVista and
shall be reasonably satisfied with the result of such review.

Section 7.02 Right of OncoVista to Abandon. OncoVista’s Board of Directors shall
have the right to abandon or terminate the Merger if any of the following shall
not be true or shall not have occurred, as the case may be, as of the specified
date or dates:

(a) All representations and warranties of AVUG and Acquisition contained in this
Agreement shall be accurate when made and, in addition, shall be accurate as of
the Effective Time as though such representations and warranties were then made
in exactly the same language by AVUG and Acquisition and regardless of knowledge
or lack thereof on the part of AVUG and Acquisition or changes beyond their
control; as of the Effective Time, AVUG and Acquisition shall have performed and
complied with all covenants and agreements and satisfied all conditions required
to be performed and complied with by them at or before the Effective Time by
this Agreement; and OncoVista shall have received certificates executed by the
chief executive officer and the chief financial officer of AVUG and the chief
executive officer and the chief financial officer of Acquisition, dated the
Effective Time, to that effect.
 
31

--------------------------------------------------------------------------------

 
(b) OncoVista shall have received at the Effective Time, certificates executed
by the chief executive officer and the chief financial officer of AVUG and the
chief executive officer and the chief financial officer of Acquisition, dated as
of such dates, to the effect that they have carefully examined the Periodic
Reports, and any amendment or supplement thereto, and, to the best of their
knowledge, (i) neither any Periodic Report, nor any amendment or supplement
thereto (A) contains an untrue statement of a material fact or (B) omits to
state a material fact required to be stated therein or necessary to make the
statements therein not false or misleading, provided in each case that such
untrue statement or omission relates to information furnished by or on behalf
of, or pertaining to, AVUG, Acquisition, or any AVUG security holder, (ii) since
the date of the filing of any Periodic Report, no event with respect to AVUG,
Acquisition, or any AVUG security holder has occurred which should have been set
forth in an amendment or a supplement to such Periodic Report which has not been
set forth in such an amendment or supplement, and (iii) any contract, agreement,
instrument, lease, or license regarding AVUG or Acquisition required to be filed
as an exhibit to any Periodic Report has been filed as an exhibit to or has been
incorporated as an exhibit by reference into such Periodic Report.

(c) AVUG and Acquisition shall have delivered to OncoVista at or prior to the
Effective Time such other documents (including certificates of officers of AVUG
or of Acquisition) as OncoVista may reasonably request in order to enable
OncoVista to determine whether the conditions to its obligations under this
Agreement have been met and otherwise to carry out the provisions of this
Agreement.
 
(d) All actions, proceedings, instruments, and documents required by AVUG or
Acquisition to carry out this Agreement or incidental thereto and all other
related legal matters shall be subject to the reasonable approval of OncoVista,
and AVUG or Acquisition shall have furnished such counsel such documents as
OncoVista may have reasonably requested for the purpose of enabling them to pass
upon such matters.

(e) At the Effective Time there shall not be pending any legal proceeding
relating to, or seeking to prohibit or otherwise challenge the consummation of,
the transactions contemplated by this Agreement, or to obtain substantial
damages with respect thereto.
 
(f) There shall not have been any action taken, or any law, rule, regulation,
order, judgment, or decree proposed, promulgated, enacted, entered, enforced, or
deemed applicable to the transactions contemplated by this Agreement by any
federal, state, local, or other governmental authority or by any court or other
tribunal, including the entry of a preliminary or permanent injunction, which,
in the reasonable judgment of OncoVista, (i) makes this Agreement, the Merger,
or any of the other transactions contemplated by this Agreement illegal, (ii)
results in a delay in the ability of AVUG, Acquisition, or OncoVista to
consummate the Merger or any of the other transactions contemplated by this
Agreement beyond December 31, 2007, or (iii) otherwise prohibits, restricts, or
delays consummation of the Merger or any of the other transactions contemplated
by this Agreement or impairs the contemplated benefits to the stockholders of
OncoVista of this Agreement, the Merger, or any of the other transactions
contemplated by this Agreement.
 
32

--------------------------------------------------------------------------------

 
(g) (i)  If required, the OTC Bulletin Board shall, at or prior to the Effective
Time, have approved the inclusion of the AVUG Common Stock to be issued in the
Merger.

(ii) The AVUG Common Stock shall be included for quotation on the OTC Bulletin
Board.
 
(h) The parties to this Agreement shall have obtained at or prior to the
Effective Time all unconditional written approval to this Agreement and to the
execution, delivery, and performance of this Agreement by each of them of
relevant governmental authorities having jurisdiction over AVUG, Acquisition, or
OncoVista or the subject matter of this Agreement.

(i) At or prior to the Effective Time, if required, AVUG and Acquisition shall
have made all filings, and taken all actions, necessary to comply with all
applicable “blue-sky” laws with regard to the issuance of AVUG Common Stock as
contemplated by this Agreement other than the filing of Form D up to 15 days
following the Effective Time. Without limiting the generality of the foregoing,
any prescribed periods within which a “blue sky” or securities law administrator
may disallow AVUG’s or Acquisition’s notice of reliance on an exemption from
such state’s requirements, shall have elapsed at or prior to the Effective Time.

(j) The parties to this Agreement shall have obtained at or prior to the
Effective Time all consents required for the consummation of the Merger and the
other transactions contemplated by this Agreement from any unrelated third party
to any contract, agreement, instrument, lease, license, arrangement, or
understanding to which any of them is a party, or to which any of them or any of
their respective businesses, properties, or assets are subject.
 
(k) OncoVista shall conduct a due diligence review of AVUG and Acquisition and
same shall be satisfactory in the reasonable opinion of OncoVista.
 
VIII. ADDITIONAL TERMS OF ABANDONMENT

Section 8.01 Mandatory Abandonment. The Merger shall be abandoned or terminated
if:

(a) in the event that the meeting of stockholders of AVUG referred to in Section
3.01 is required, the holders of at least a majority of the shares of AVUG
Common Stock outstanding and entitled to vote at such meeting of stockholders
shall not have voted in favor of the adoption and approval of this Agreement,
the Merger, and the other transactions contemplated hereby; or
 
(b) the holders of at least a majority of the shares of OncoVista Common Stock
outstanding and entitled to vote at the meeting of stockholders of OncoVista
referred to in Section 3.01 shall not have voted in favor of the adoption and
approval of this Agreement, the Merger, and the other transactions contemplated
hereby.
 
33

--------------------------------------------------------------------------------

 
Section 8.02 Optional Abandonment. In addition to the provisions of Article VII,
the Merger may be abandoned or terminated at or before the Effective Time
notwithstanding adoption and approval of this Agreement, the Merger, and the
other transactions contemplated hereby by the stockholders of the parties
hereto:

(a) by mutual agreement of the Boards of Directors of AVUG, Acquisition, and
OncoVista;

(b) at the option of AVUG’s and Acquisition’s Boards of Directors or OncoVista’s
Board of Directors, if the Effective Time shall not have occurred on or before
December 31, 2007;

(c) at the option of AVUG’s and Acquisition’s Boards of Directors, if facts
exist which render impossible compliance with one or more of the conditions set
forth in Section 7.01 and such are not waived by AVUG; and
 
(d) at the option of OncoVista’s Board of Directors, if facts exist which render
impossible compliance with one or more of the conditions set forth in Section
7.02 and such are not waived by OncoVista.

Section 8.03 Effect of Abandonment. If the Merger is abandoned or terminated as
provided for in Article VII or in this Article VIII, except for Sections
5.01(i), 5.02(e) and 5.02(n), and Article IX, this Agreement shall forthwith
become wholly void and of no further force or effect without liability on the
part of either party to this Agreement or on the part of any officer, director,
controlling person (if any), employee, counsel, agent, or stockholder thereof;
provided, however, that nothing in this Section 8.03 shall release AVUG,
Acquisition, or OncoVista or any officer, director, controlling person (if any),
employee, counsel, agent, or stockholder thereof from liability for a willful
failure to carry out its respective obligations under this Agreement.
 
IX. MISCELLANEOUS

Section 9.01 Further Actions. At any time and from time to time, each party
agrees, at its expense, to take such actions and to execute and deliver such
documents as may be reasonably necessary to effectuate the purposes of this
Agreement.

Section 9.02 Availability of Equitable Remedies. Since a breach of the
provisions of this Agreement could not adequately be compensated by money
damages, any party shall be entitled, either before or after the Effective Time,
in addition to any other right or remedy available to it, to an injunction
restraining such breach or threatened breach and to specific performance of any
such provision of this Agreement, and, in either case, no bond or other security
shall be required in connection therewith, and the parties hereby consent to the
issuance of such an injunction and to the ordering of specific performance.
 
34

--------------------------------------------------------------------------------

 
Section 9.03 Survival; Knowledge. The covenants, agreements, representations,
and warranties contained in or made pursuant to this Agreement shall not survive
the Effective Time, except for those contained in or made pursuant to Sections
2.01, and Article IX. The statements contained in any document executed by AVUG
or Acquisition relating hereto or delivered to OncoVista in connection with the
transactions contemplated hereby or thereby, or in any statement, certificate,
or other instrument delivered by or on behalf of AVUG or Acquisition pursuant
hereto or thereto or delivered to OncoVista in connection with the transactions
contemplated hereby or thereby shall be deemed representations and warranties,
covenants and agreements, or conditions, as the case may be, of AVUG and
Acquisition hereunder for all purposes of this Agreement (including all
statements, certificates, or other instruments delivered pursuant hereto or
thereto or delivered in connection with this Agreement, the Merger, or any of
the other transactions contemplated hereby or thereby). The statements contained
in any document executed by OncoVista relating hereto or delivered to AVUG or
Acquisition in connection with the transactions contemplated hereby or thereby,
or in any statement, certificate, or other instrument delivered by or on behalf
of OncoVista pursuant hereto or thereto or delivered to AVUG or Acquisition in
connection with the transactions contemplated hereby or thereby shall be deemed
representations and warranties, covenants and agreements, or conditions, as the
case may be, of OncoVista hereunder for all purposes of this Agreement
(including all statements, certificates, or other instruments delivered pursuant
hereto or thereto or delivered in connection with this Agreement, the Merger, or
any of the other transactions contemplated hereby or thereby). For the purposes
of this Agreement, where an entity represents and warrants a fact “to its
knowledge” or “to the best of its knowledge” it shall have imputed to its
knowledge only the actual conscious awareness of facts or other information,
without investigation, of the executive officers and the chief financial officer
of the entity and its subsidiaries. Where an individual represents and warrants
a fact “to the best of the individual’s knowledge” the individual shall have
imputed to that individual only the actual conscious awareness of facts or other
information, without investigation, of that individual.

Section 9.04 Modification. This Agreement sets forth the entire understanding of
the parties with respect to the subject matter hereof (except as provided in
Section 9.03) and supersedes all existing agreements among them concerning such
subject matter. This Agreement may be amended prior to the Effective Time
(notwithstanding stockholder adoption and approval) by a written instrument
executed by AVUG, Acquisition, and OncoVista with the approval of their
respective Boards of Directors; provided, however, that no such amendment shall,
without stockholder adoption and approval by an appropriate vote by stockholders
of the Constituent Corporation whose stockholders have been adversely affected,
change the number of shares of AVUG Common Stock which may be issued pursuant to
this Agreement, or materially and adversely affect the rights of AVUG or
OncoVista stockholders. No amendment to accelerate or postpone the Effective
Time shall be deemed to change such number of shares or affect adversely the
rights of the AVUG or OncoVista stockholders.
 
35

--------------------------------------------------------------------------------

 
Section 9.05 Notices. All notices under this Agreement must be in writing and
addressed, if to AVUG or Acquisition, to its corporate secretary, and if to
OncoVista, to its chief executive officer. Any notice or other communication in
connection with this Agreement shall be deemed to have been given (i) if
personally delivered to a party, when so delivered, (ii) (A) if by certified
mail, three business days after mailing or (B) if by Federal Express or other
recognized next day carrier timely posted for next business day delivery, the
next business day following such timely posting, to the address of such party
set forth in the preamble to this Agreement (or to such other address as the
party shall have furnished in writing in accordance with the provisions of this
Section 9.05), or (iii) if by facsimile, once transmitted (provided that the
appropriate answer back or telephonic confirmation is received), if to AVUG at
14785 Omicron Drive, Suite 104, San Antonio, Texas 78245 and if to OncoVista at
14785 Omicron Drive, Suite 104, San Antonio, Texas 78245. Either party may
change the address or facsimile number to which notices or other communications
hereunder are to be delivered by giving the other party notice in the manner set
forth.

Section 9.06 Waiver. Any waiver by any party of a breach of any term of this
Agreement shall not operate as or be construed to be a waiver of any other
breach of that term or of any breach of any other term of this Agreement. The
failure of a party to insist upon strict adherence to any term of this Agreement
on one or more occasions will not be considered a waiver or deprive that party
of the right thereafter to insist upon strict adherence to that term or any
other term of this Agreement. Any waiver must be in writing and be authorized by
a resolution of the Board of Directors or by an officer of the waiving party. No
party shall have the right to waive compliance with Section 8.01, the second
sentence of Section 9.04, or this sentence.
 
Section 9.07 Binding Effect. The provisions of this Agreement shall be binding
upon and inure to the benefit of AVUG, Acquisition, and OncoVista and their
respective successors and assigns and shall inure to the benefit of each
indemnitee hereunder and its successors and assigns (if not a natural person)
and his assigns, heirs, and personal representatives (if a natural person).

Section 9.08 No Third-Party Beneficiaries. This Agreement does not create, and
shall not be construed as creating, any rights enforceable by any person not a
party to this Agreement except for the OncoVista stockholders with respect to
Sections 2.01, and except as provided in Section 9.07.
 
Section 9.09 Severability.  If any provision of this Agreement is invalid,
illegal, or unenforceable, the balance of this Agreement shall remain in effect,
and if any provision is inapplicable to any person or circumstance, it shall
nevertheless remain applicable to all other persons and circumstances, provided,
however, that the economic and legal substance of the transactions contemplated
by this Agreement are not affected in any way materially adverse to any party
hereto.

Section 9.10 Headings. The headings in this Agreement are solely for convenience
of reference and shall be given no effect in the construction or interpretation
of this Agreement.
 
36

--------------------------------------------------------------------------------

 
Section 9.11 Counterparts; Governing Law. This Agreement may be executed in any
number of counterparts, each of which shall be deemed an original, but all of
which together shall constitute one and the same instrument. It shall be
governed by and construed in accordance with the laws of the State of Delaware,
without giving effect to conflict of laws. Any action, suit, or proceeding
arising out of, based on, or in connection with this Agreement, any document
relating hereto or delivered in connection with the transactions contemplated
hereby, any statement, certificate, or other instrument delivered by or on
behalf of, or delivered to, any party hereto or thereto in connection with the
transactions contemplated hereby or thereby, any breach of this Agreement or
such other document, the Merger, or the other transactions contemplated hereby
or thereby may be brought only in the state courts of the State of Delaware
located in Kent County, or in the United States District Court for the District
of Delaware, and each party covenants and agrees not to assert, by way of
motion, as a defense, or otherwise, in any such action, suit, or proceeding, any
claim that it is not subject personally to the jurisdiction of such court if it
has been duly served with process, that its property is exempt or immune from
attachment or execution, that the action, suit, or proceeding is brought in an
inconvenient forum, that the venue of the action, suit, or proceeding is
improper, or that this Agreement or the subject matter hereof may not be
enforced in or by such court.
 

[REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]
 
37

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, this Agreement has been executed by duly authorized officers
of each of the parties hereto as of the date first above written.
 

 
AVIATION UPGRADE TECHNOLOGIES, INC.
     
By
/s/ Alexander L. Weis
   
Name: Alexander L. Weis, Ph.D.
   
Title: Chief Executive Officer
         
ONCOVISTA ACQUISITION CORP.
       
By
/s/ Alexander L. Weis
   
Name: Alexander L. Weis, Ph.D.
   
Title: Chief Executive Officer
         
ONCOVISTA, INC.
       
By
/s/ Alexander L. Weis
   
Name: Alexander L. Weis, Ph.D.
   
Title: Chief Executive Officer

--------------------------------------------------------------------------------