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                                 PROMISSORY NOTE                   EXHIBIT 10.23

$172,000.00                                                        San Diego, CA
                                                               November 30, 1998


        For value received, the undersigned hereby promises to pay to Discovery
Partners International, Inc., a California corporation, or order (the "Holder")
at 11149 North Torrey Pines Road, La Jolla, CA 92037, the principal amount of
One Hundred Seventy Two Thousand Dollars ($172,000.00), plus interest accrued
thereon.

        This Promissory Note shall bear 4.51 percent simple interest per annum,
until due (upon maturity or acceleration), and after it is due (upon maturity or
acceleration) shall bear interest at 10 percent per annum, compounded annually.

        Accrued interest shall be due and payable on each anniversary of the
date of this Promissory Note. All principal and remaining accrued interest shall
be due and payable in a lump sum on November 30, 2005.

        This Promissory Note may be prepaid at any time, without premium or
penalty; provided, that any such prepayment must be of the entire principal
amount plus all accrued interest.

        Upon the happening of any of the following events, Holder may, at its
option, declare immediately due and payable the entire unpaid principal amount
of this Promissory Note, together with all interest thereon, plus any other
amounts payable at the time of such declaration pursuant to this Promissory
Note. Such events are the following: (1) the maker of this Promissory Note
("Maker") shall admit in writing his inability to pay his debts as they become
due, shall make a general assignment for the benefit of creditors or shall file
any petition or action for relief under any bankruptcy, reorganization,
insolvency or moratorium law, or any other law or laws for the relief of, or
relating to, debtors; or (2) an involuntary petition shall be filed against
Maker under any bankruptcy, reorganization, insolvency or moratorium law, or any
other law or laws for the relief of, or relating to, debtors unless such
petition shall be dismissed or vacated within sixty (60) days of the date
thereof; or (3) Maker shall fall to make any payment of interest when due; or
(4) Maker's employment with the Holder shall, for any reason whatsoever, cease.

        This Promissory Note is secured by a Pledge Agreement of even date
herewith. This is a full-recourse Promissory Note. The Holder is not required to
proceed first against the Pledge Agreement collateral.

        The acceptance by Holder of any payment hereunder which is less than the
payment in full of all amounts due and payable at the time of such payment shall
not constitute a waiver of the right to accelerate at that time or any
subsequent time or nullify any prior acceleration without the express consent of
Holder except as and to the extent otherwise provided by law.

        The Maker of this Promissory Note waives diligence, presentment, protest
and demand and also notice of protest, demand, dishonor and nonpayment of this
Promissory Note, and expressly agrees that this Promissory Note, or any payment
hereunder, may be extended from


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time to time and consents to the acceptance of security, if any, or the release
of security, if any, from this Promissory Note, all without in any way affecting
the liability of the Maker.

        The right to plead any and all statutes of limitations as a defense to
any demand on this Promissory Note, or any instrument securing this Promissory
Note, or any and all obligations or liabilities arising out of or in connection
with this Promissory Note, is expressly waived by Maker to the fullest extent
permitted by law.

        No extension of the time for the payment of this Promissory Note, or any
installment hereof, made by agreement by the Holder hereof with any person now
or hereafter liable for the payment of this Promissory Note shall affect the
original liability under the terms of this Promissory Note by Maker even if it
is not a party to such agreement.

        If Holder should institute collection efforts, of any nature whatsoever,
to attempt to collect any and all amounts due hereunder upon the default of
Maker, Maker shall be liable to pay to Holder immediately and without demand all
reasonable costs and expenses of collection incurred by Holder, including
without limitation reasonable attorneys fees, whether or not suit or other
action or proceeding be instituted and specifically including but not limited to
collection efforts that may be made on appeal or through a bankruptcy court, and
all such sums shall be fully secured by all instruments, if any, securing this
Promissory Note.

        The provisions of this Promissory Note are intended by Maker to be
severable and divisible and the invalidity or unenforceability of a provision or
term herein shall not invalidate or render unenforceable the remainder of this
Promissory Note or any part thereof.

        This Promissory Note shall be governed by and construed and interpreted
in accordance with the internal laws of the State of California.

                                       /s/ Riccardo Pigliucci
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                                       Riccardo Pigliucci

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