bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclitols. XXVI. The solvolysis of tosylinositols in acetic acid
Authors: Angyal SJ , Bender VJ , Gilham PT , Hoskinson RM , Pitman ME
Published: September 2010

Several monotosyl
derivatives of inositols have been solvolysed in boiling acetic acid. In some
cases the reaction occurs with predominant inversion and then presents a method
suitable for the synthesis of rare cyclitols, e.g., allo-
and muoo- inositols and their methyl ethers. In other
cases, inversion and retention occur to a similar extent.
Flavan derivatives. XVI. Acid-catalysed reactions of secondary benzyl alcohols and 1-tetralols in methanol
Authors: Clark-Lewis JW , Nair V
Published: September 2010

Under solvolytic
conditions I-phenylpropan-1-01 and its p-methyl and
p-methoxy derivatives gave 1 -arylprop- 1 -enes. 1 -(3,4-Dimethoxypheny1)propan- 1-01 behaved similarly, but in addition gave the
known propene dimer di-isohomogenol (di-isoeugenol dimethyl ether). Ring-proton coupling constants
(J 7.3 and 9.2 CIS) appear consistent with a staggered
trans-trans-configuration for this dimer,$ in agreement with earlier
interpretations of chemical evidence. 1-(2,4,6-Trimethoxy-
pheny1)propan-1-01 proved very
reactive and gave the symmetrical dibenzyl ether
under very mild acid catalysis, but with higher acid concentration it gave the
prop-1-ene accompanied by a 1,l-diarylpropane
formed by electrophilic displace- ment of the propan-1-01 side-chain. Tetralin-1-01 and cis- and
trans-tetralin-1,2-diols, which lack activating aromatic substituents, were
stable towards methanolic acetic acid (3%) or hydrogen chloride (3%). 6-Methoxytetralin-1-01, however, gave 1,6-dimethoxytetralin
with methanolic 0.001% acetic acid, but with higher tetra101
concentration it gave the symmetrical bis-tetralyl
ether. 6-Methoxytetralin-1-01 gave 3,4-dihydro-6-methoxynaphthalene and its known dimer when heated with
methanolic hydrogen chloride (1%). Nuclear magnetic resonance showed that the tetralins are conformationally
mobile, and the spectra were consistent with rapid interconversion
of two half-chair conformations. 3-Phenyltetralin-1-01
(tetralin analogue of flavan-3-01) was obtained in
the l,3-cis-form and existed in the confor- mationally stable half-chair form with both substituents
equatorial. Spin-spin coupling constants of cis- and trans-carbonates of
tetralin-1,2-diols are close to values recorded for their flavandiol
analogues.
(+)-(5S)-δ-Lactone of 5-hydroxy-7-phenylhepta-2,6-dienoic acid, a natural product from Cryptocarya caloneura (Scheff.) Kostermans
Authors: Hlubucek JR , Robertson AV
Published: September 2010

The structure, including
absolute configuration, of a new compound extracted from Cryptocarya caloneura (Scheff.) Kostermans
has been determined by degradation as the (+)-(5S)-δ-lactone of
5-hydroxy-7- phenylhepta-2,6-dienoic acid. The structure has been confirmed by
synthesis of its racemate.
Pyridinium ylids in synthesis. III. Synthesis of indolizines
Authors: Henrick CA , Ritchie E , Taylor WC
Published: September 2010

Treatment of pyridinium,
quinolinium, and isoquinolinium ylids with acetylenes yields indolizine
derivatives. Pyridinium phenacylid with iodine in dimethylacetamide gives
1,2,3-tribenzoylindolizine. Decomposition of pyridinium phenacylid in the
presence of copper or copper oxide affords 1,3-dibenzoylindolizine.
Faradaic impedance measurements of the ferrous/ferric citrate system
Authors: Elliott D
Published: September 2010

An examination of the
ferrous/ferric citrate system has been made by the faradaic impedance
technique. Determination of the reaction mechanism by the dependence of the
rate on concentration has been attempted. The results have proved ambiguous in
deciding whether the rate is controlled chemically or by the electron transfer
stage. In addition, the negative dependence of the rate on iron(II)
concentration has proved difficult to account for and a mechanism involving
iron(IV) has been tentatively proposed.
Extractives of Australian timbers. VIII. Emmolactone, a bisnor-triterpene
Authors: Eade RA , Ellis J , Simes JJH
Published: September 2010

Emmolactone, C28H38O3,
a bisnor-triterpene isolated from Emmenospermum alphitonioides F. Muell., has
been shown to possess structure (I) by chemical and spectroscopic investigation
and by convergent synthesis from ceanothenic acid.
Organoaluminium compounds. XIV. Evidence for association through unlike bridging groups
Authors: Jeffery EA , Mole T , Saunders JK
Published: September 2010

Proton magnetic resonance
spectroscopy has revealed the formation of

Me2AlXYAlMe2 from Me2AIX2Me2
and Me2AlY2AlMe2,
where X and Y are bridging groups. In the
cases studied, X = Cl, Y = Me, Br, or PhCC; X = Br, Y
= Ph, PhCC, or OPr1;
and X = PhCC, Y = Opr1.
The position of equilibrium varies widely from one case to another. Formation
of Me2AlXYAlMe2 is rapid except
when dimethylaluminium isopropoxide is one of the
reactants. The variation with
temperature of the spectra of methylaluminium sesquibromide, methylaluminium sesquichloride, and mixtures of the latter with
dimethylaluminium chloride has been examined and interpreted in terms of facile
dissociation of the double halogeno bridge with a low
probability of reassociation by way of methyl
bridges.
Constituents of some Curvularia species
Authors: Coombe RG , Jacobs JJ , Watson TR
Published: September 2010

Thirteen Gurvularia and related species were examined and
the following metabolites obtained: brefeldin A, curvularin, curvulin, curvulinic acid
derivatives, D-mannitol, 1,4,5,8-tetrahydroxy-2,6-dimethylanthraquinone,
saturated and unsaturated fatty acids, and fatty acid esters.
Catalytic deuterium exchange reactions with organics. XXXVIII. Further studies in the labelling of cycloolefins with deuterium chloride
Authors: Calf GE , Fisher BD , Garnett JL
Published: September 2010

A new method for labelling
a wide range of cycloolefins (C5 to C10,)
with isotopic hydrogen is
described in detail. The method consists of exchange with deuterium chloride or
bromide in the presence of acetic acid at temperatures of 130�. The reaction is
an addition-elimination process. Under certain conditions with some compounds,
isomerization, rearrangement, and polymerization occur as side reactions. The
advantages and limitations of the present method for labelling

cycloolefins are discussed and compared with conventional
procedures such as Wilzbach gas irradiation for
tritium and metal-catalysed exchange for both hydrogen isotopes. Possible
mechanisms for the reaction are proposed.
The alkaloids of Lamprolobium fruticosum Benth. (family Leguminosae)
Authors: Hart NK , Johns SR , Lambeton JA
Published: September 2010

Lamprolobine, a new alkaloid isolated from the leaves of Lamprolobium

fruticosum Benth. (family Leguminosae) has been shown
to be (I) by a study of its spectroscopic properties and by the formation on
acid hydrolysis of glutaric acid and (+)-1-aminomethylquinolizidine (IV). The stereochemistry of lamprolobine (I) was confirmed by the preparation of the N-acetyl
compound (V) from both lamprolobine and from epilupinine. The known alkaloid cytisine
was also isolated from L.

fruticosum leaves. A third base, isolated only from methanolic extracts of L. fruticosum,
was shown to be the ester (VIII), but it is considered to be an artefact.
Depsipeptide synthesis by accelerated active ester coupling
Authors: Stewart FHC
Published: September 2010

Protected amino acid active
esters react with α-hydroxy acid esters in the presence of several
equivalents of imidazole to form aminoaoyl hydroxy
acid derivatives in high yield. p-Nitrophenyl, 8-quinolyl,
and cyanomethyl esters have been employed as activated
carboxyl components in the reaction. Several depsipeptide
derivatives were synthesized using the accelerated active ester coupling
procedure. Pentamethylbenzyl was used extensively as
a carboxyl-protecting group in this work.
Electron impact studies. XXXI. Skeletal-rearrangement fragments in the mass spectra of anils
Authors: Bowie JH , Cooks RG , Fisher JW , McL Spotswood T
Published: September 2010

Skeletal-rearrangement
fragments are observed in the mass spectra of all anils derived from aromatic
aldehydes. The rearrangement processes have been studied by high-resolution
mass spectrometry and in certain cases by deuterium labelling. All processes are
of the general type [ABC]+ → [AC]+ +B.
The chemistry of the Euphorbiaceae. XX. Further compounds from Beyeria leschenaultii 12β,17-Dihydroxy-16α-( - )-kauran-19-oic acid
Authors: Jefferies PR , Retallack RW
Published: September 2010

The title substance was
separated from the plant as its methyl ester (IV) and its structure
established, partly by conversion into 16α-(-)-kaurane-17,19-dioic
acid (VIII) and by other chemical and N.M.R. evidence which locates the
secondary hydroxyl. Four known kauranes and a flavone were also isolated from the plant. The conformation of ring c
in the 12-oxygenated compounds is discussed.
Mass spectrometric studies. III. Bis(diphenylamino)methane, Bis(diphenylphosphino)methane, Bis(diphenylarsino)methane, and related compounds
Authors: Colton R , Porter QN
Published: September 2010

The compounds listed in the
title, together with the analogous 1,2-bis(diphenyl-phosphino)- and
1,2-bis(diphenylarsino)-ethanes, as well as triphenylarsine have been subjected
to electron bombardment at 70 eV. The nitrogen compound undergoes simple
fragmentation whereas the diphosphines and the diarsines undergo fragmentations
which clearly demonstrate migration of phenyl groups to give, inter alia,
triphenylphosphine and triphenylarsine cations. These subsequently fragment in
the same way as intact triphenylphosphine and triphenylarsine molecules.
Ultrasonic studies in molten pyridinium chloride solutions
Authors: Reinsborough VC , Valleau JP
Published: September 2010

Ultrasonic absorptions in
the 13-91 Mc/s region and ultrasonic velocities have been measured in molten
pyridinium chloride containing various concentrations of anilinium
chloride or cetyldimethylbenzylammonium chloride as
solutes, at 155�. Adiabatic compressibilities
were calculated for both systems. The anilinium
chloride system behaved normally, but with the larger cation a sharp change in
both absorption and velocity occurred at a concentration of 0.06m, in agreement
with measurements of other physico-chemical
properties. For more concentrated solutions, a pronounced ultrasonic
relaxation was found, having a characteristic frequency of about 40 Mc/s; this
may be interpreted in terms of a simple micelle growth mechanism.
Vibrational frequencies of deuterated ethylenes: Green's function method
Authors: Ramaswamy R , Devarajan V
Published: September 2010

The frequencies of the
partly deuterated ethylenes were predicted by the method of Green's function
analysis. These values are compared with those obtained by the average rule and
complete isotope rule. It is shown that the Green's function analysis gives a
better insight into the isotopic rule from the molecular dynamic point of view.
Viscosity and conductance micellar studies in molten pyridinium chloride
Authors: Bloom H , Reinsborough VC
Published: September 2010

Viscosity and conductance
measurements in cetyldimethylbenzylammonium chloride solutions in molten
pyridinium chloride are in agreement with other studies that indicate that
micellization commences at 0.06-0.07m at 155�. Effective molal volumes, bulk
viscosities, and equivalent conductivities for this system and a comparison
system (anilinium chloride as solute), have been calculated. The data suggest
that around 0.12m the micelles are stabilized in a size distribution comprised
mainly of asymmetric micelles. Molten pyridinium chloride behaves
ultrasonically as an associated liquid. The densities and viscosities of 0.5M
KCl sucrose solutions (25-40% sucrose) are also supplied as calibration data
for electroviscometers in the range 2-5 cP.
The formation of hydroxy and chloro complexes of iron(III) in chloride and perchlorate media
Authors: Fordham AW
Published: September 2010

The hydrolysis of iron(III)
has been studied by spectrophotometric methods in KaClO4,
NaCl, and CaCl2
solutions all of the same ionic strength 0.15M. The measured values of the
hydrolysis constants, expressed in a form which allows for association of iron with
the supporting medium, were 14.5 x 10-4 in NaClO4,
8.8 x 10-4 in NaCl, and 10.9 x 10-4
in CaCl2. In addition, the extent of complex
formation between iron(III) and chloride ions has been measured in perchlorate
solutions of the same ionic strength 0.15M. Assuming that only chloro complexes
were formed in these systems, the stability constant of FeCl2+
formation was found to be 4.0. ��� All the results obtained were sufficiently
consistent with each other, within experimental error, that the inclusion of terms
to account for iron-perchlorate association was unwarranted. However, if
iron-perchlorate association was assumed to exist and the results were treated
accordingly, the stability constant of the associated complex was estimated to
be 1.8.
Alkaloids of Jasminum species (family Oleaceae). II. Isolation of a new monoterpenoid alkaloid and other constituents
Authors: Hart NK , Johns SR , Lamberton JA
Published: September 2010

A new monoterpenoid
alkaloid (VI), closely related to the alkaloid (VII) from Rauwolfia
verticillata, has been isolated from a Jasminum species from New Guinea. The
same Jasminum species contains a substance C11H16O5
for which the probable structure (IX) has been assigned from a study of its
100-Mc/s N.M.R. spectrum. The lignan pinoresinol has been isolated from the
Queensland species Jasminum simplicifolium Forst.
Solvent effects on the rates of miscellaneous nucleophile-promoted reactions in aqueous-alcoholic solvent mixtures
Authors: Anderson RJ , Ang P , England BD , McCann VH , McLennan DJ
Published: September 2010

The rates of E2 elimination
from DDT and SN2 substitution on allyl bromide by alkoxide and
hydroxide ions have been measured using aqueous-alcoholic solvent mixtures. The
results are anomalous in terms of previous theories. The E2 hydrogen nucleophilicity
order of OEt- > OMe-
> OH- towards 2-phenethyl bromide in dioxan has been obtained by
extrapolating rates of reaction in alkaline dioxan-alcohol or dioxan-water
mixtures to 100% dioxan. The nucleophilicity order contrasts with the basicity
order: OEt- > OH- > OMe-
but is the same as the carbon nucleophilicity order. The validity is questioned
of using similar carbon- nucleophilicity and elimination-reactivity orders as
positive evidence for the E2C mechanism of eliminations promoted by weak bases
which are also strong carbon nucleophiles.
Cobalt(II) complexes of 2,3,5,6-Tetrakis(2-pyridyl)pyrazine and 2,4,6-Tris-(2-pyridyl)-1,3,5-triazine
Authors: Goodwin HA , Sylva RN , Vagg RS , Watton EC
Published: September 2010

Bis-ligand cobalt(II) complexes
of 2,4,6-tris(2-pyridyl)-1,3,5-triazine and 2,3,5,6.tetrakis(2-pyridyl)pyrazine
have been prepared. The conductivities of the complexes in nitromethane
solution correspond to values expected for bi-unielectrolytes. The temperature
dependence of their magnetism has shown that in some instances there exists a
spin-state equilibrium in the metal atom while in others the metal atom is
spin-free and Curie-Weiss laws are obeyed.
Diterpenoids. XXI. 8-Oxo-14-norlabdanes
Authors: Carman RM , Cowley DE , Marty RA
Published: September 2010

Structure and optical rotation
are correlated for some 8-oxo-14- norlabdanes which all have a negative
rotation at the sodium D line and a negative Cotton effect. A correlation of
communic acid with agathic acid is shown to be correct in spite of some erroneous
rotations in the original publication.
Octahedral cobalt(III) complexes of the chloropentammine type. XVIII. Hydrolysis of some Chloroanilinebis(ethylenediamine)cobalt(III) complexes, and a rationalization for the conjugate-base and ion-pair mechanisms
Authors: Chan SC , Lau OW
Published: September 2010

The kinetics for the
appearance of chloride ion from aqueous solutions of the cis-chloroanilinebis(ethylenediamine)cobalt(III)
cation are determined over the pH ranges of 2-3 at 40.0� and of 8-9 at 0�. By
using self-buffered mixtures, the rate constants for the reaction are also
measured at 40.0� as a function of the concentration of complex or of free
aniline. The results are discussed in terms of the conjugate- base mechanism. A
rationalization of this mechanism and the ion-pair mechanism is proposed to incorporate
the base hydrolysis of other previously investigated systems where the
complexes are decidedly much less acidic. At a higher temperature (65.0�), both
chloride ion and aniline are liberated at similar rates, and the process is
treated as parallel first-order reactions. By using complexes with meta- and
para-substituted anilines, the effect of the methyl substituent on reactivity
is studied.
E.S.R. of nitroxide radicals. I. Photolysis of indoles, phenols, disulphides, and thiols
Authors: Leaver IH , Ramsay GC , Suzuki E
Published: September 2010

The formation of stable
nitroxide radicals during the photochemical decomposition of a number of
indoles, phenols, disulphides, and thiols in the presence of a nitrosoalkane
radical scavenger has been demonstrated. The predominant e.s.r. spectrum
obtained with dibutyl disulphide or butane-1-thiol consists of a simple triplet
hyperfine splitting with aN 18.5 G and g
2.0071, attributed to the trapping of butane-1-thiyl
radicals. Phenol and indole give similar triplet spectra with aN 15.55 G, g 2.0061, and aN
16.26 G, g 2.0060, respectively. ��� The formation of trichloromethyl radicals
during the photolysis of indole in carbon tetrachloride has been confirmed by
analysis of the e.s.r. spectrum of the trichloromethyl nitroxide radical using
a least- squares curve-fitting procedure. Isotropic hyperfine splitting
constants for 14N, 35Cl, and 37Cl have been obtained.
The activity coefficients of cadmium chloride in water and sodium chloride solution at 25°
Authors: Reilly PJ , Stokes RH
Published: September 2010

The activity coefficients
of cadmium chloride in water and sodium chloride solution have been measured.
The data have been used to calculate the stability constants of the cadmium
chloride complexes. The results are compared with the results of previous work
and reasons for the discrepancies are suggested.
Chemistry of the Podocarpaceae. XXV. Conversion of 8α,13β-epoxylabd-14-en-2-one into compounds with ambergris-type odours
Authors: Cambie RC , Joblin KN , McCallum NK
Published: September 2010

2-Oxomanoyl
oxide (2) has been converted into the 2-hydroxy ether (17) and the 2-keto ether
(19), both of which possess ambergris-type odours
similar to but much weaker than that of the odoriferous compound (14). The
route affording the highest overall yield is via the intermediates (5), (43),
(23), and (39), which gives 23% of the 2-keto ether (19) and 17% of the hydroxy
ether (17).
Cyclic phosphines and arsines. II. Cyclic arsines
Authors: Elmes PS , Middleton S , West BO
Published: September 2010

The constitutions of the cyclopolyarsines (AsR)n
(R = methyl, ethyl, n-propyl, and phenyl) have been investigated by nuclear
magnetic resonance and mass spectrometric techniques. A systematic study of
their fragmentation under electron impact at different ionization potentials
has confirmed the presence of pentameric alkyl and hexameric phenyl cyclic arsines. Variable temperature
N.M.R. spectra obtained for pentamethylcyclopentaarsine
have been interpreted in terms of a rapid

pseudorotation process. Some mixed methylphenyl
cyclic arsines have been identified.
Orbital valence force field in tetrahedral oxides and oxyanions of transition metals
Authors: Prasad M , Pandey AN
Published: September 2010

The orbital valence force
field has been used to calculate the force constants of some oxides and
oxyanions of transition metals, e.g. MnO42-,
MnO43-, RuO4, RuO4-,
Ru042-, and OsO4. The force constants are compared with the Urey-Bradley force constants and have been discussed
briefly in relation to relative stabilities of the corresponding ions. The
applicability of the Lennard-Jones potential, to approximate the interaction
between non-bonded atoms, has been examined.
Resolution of 4-aminoflavan into its optical isomers; nuclear magnetic resonance spectra of 4-aminoflavan and 3-aminoflavanone derivatives
Authors: Bognar R , Clark-Lewis JW , Liptakne-Tokes A , Rakosi M
Published: September 2010

(�)-2,4-cis-4-Aminoflavan
obtained by reduction of 4-oximinoflavan has been
resolved into enantiomeric forms by fractional
crystallization of its amine salts with (+)-camphor-10-sulphonic
acid and with (-)-di-O-benzoyltartaric acid. The
pairs of diastereoisomeric salts thus separated were converted into (+)- and
(-)-2,4-cis-4-aminoflavan hydrochlorides, from which
the free bases and the optically active N-acetyl and N-benzoyl derivatives were prepared. N.m.r. data
unequivocally establish the 2,4-cis
configuration of all these 4-substituted flavan
derivatives. 3-Aminoflavanone
prepared by the Neber rearrangement of 4-oximinoflavan, and also by controlled catalytic
hydrogenation of 3-oximinoflavanone, is shown from
N.M.R. data on suitable derivatives to have the 2,3-trans configuration.
A unified treatment of the electrochemical photo effect at metal electrodes
Authors: Matthews DB
Published: September 2010

The electrochemical photo
effect is analysed in terms of the Gurney model of electrochemical charge
transfer. Various absorption processes and their effect on the proton discharge
step of the hydrogen evolution reaction are treated and the dependence of the
photo effect on radiation frequency and electrode potential is derived for each
absorption process. The analysis is compared with the presently available
experimental results and a useful application of the photo effect is outlined.
Chemistry of the Podocarpaceae. XXIX. The preparation of 6-oxygenated derivatives of Abieta-8,11,13-trien-18-oic acid
Authors: Cambie RC , Franich RA
Published: September 2010

��� Peracid oxidation of the enol acetate (23)
derived from the C 7 ketone (6) provides a method for introducing an oxygenated
substituent into the C 6 position of abieta-8,11,13-trien-18-oic acid (1).
Reduction of the keto acetate (10) with sodium borohydride and hydrogenolysis
of the C 7 hydroxy group of the hydroxy acetate (28) affords the 6-acetate (33)
in 55% overall yield from methyl abieta- 8,11,13-trien-18-oate (2). Hydrolysis
of the acetoxy ester (33) followed by re-methylation of the C 4 carboxy group
and oxidation of the hydroxy ester (34) gives the C 6 ketone (35).
Electron impact studies. LXIII. Negative-ion mass spectrometry of functional groups. Rearrangements of the nitrophthalic anhydrides
Authors: Blumenthal T , Bowie JH
Published: September 2010

The negative-ion mass
spectra of 3- and 4-nitrophthalic anhydride contain a series of rearrangement
ions. One of these, an M-CO2 ion, is mainly produced by loss of CO
from the anhydride unit together with an oxygen of the nitro group.
The proton magnetic resonance spectra of N-nitroso derivatives of sarcosine, proline and iminodiacetic acid
Authors: Stewart FHC
Published: September 2010

The proton magnetic
resonance spectra of various N-nitroso derivatives of sarcosine, L-proline, and
iminodiacetic acid, including some protected dipeptides, have been obtained.
Magnetic non-equivalence and conformational isomerism arising from restricted rotation
of the nitroso group are discussed in relation to the reported behaviour of
other nitrosamines. Long-range shielding effects on protons at a considerable
distance from the anisotropic nitrosamino centre were readily detected with
these compounds.
Hydrogen bonding in chloroform and ether mixtures
Authors: Baker JR , Watson ID , Williamson AG
Published: September 2010

The hydrogen bonding
between chloroform and di-n-alkyl ethers has been
studied over the temperature range -50�C to + 50�C using proton magnetic
resonance. The measurements of chemical shift have been interpreted in terms of
the formation of a 1 : 1 complex between the chloroform and the ether. Mole
fraction association constants in the range 1-5 were found. The enthalpies of
formation of the complexes deduced from the temperature coefficients of the
equilibrium constants varied from -8 kJ mol-1 to -11.7 kJ mol-1.
Multipolar third-order non-pairwise additivity of intermolecular forces: Effects on crystal properties and third virial coefficients
Authors: Johnson CHJ , Spurling TH
Published: September 2010

In this paper we give the
results of computing the third virial coefficient and the cohesive energy of
the crystal for argon taking into account the higher-order multipole terms in
the long-range three- body interaction as recently calculated by Bell. The Barker-Pompe potential has been used as the two-body potential
function. We find that the third virial coefficient values for argon computed
with this more complete non-additive energy function agree very much better
with the experimental values than when only the triple-dipole term is used.
This is particularly true at lower temperatures. The results also show that
better agreement would be obtained if some form of repulsive non- addivity were included in the computation. For the cohesive
energy of the crystal we find that the dipole-dipole-quadrupole energy is
one-third as large as the triple-dipole energy and so cannot be neglected in
these lattice computations. Furthermore, we find that these higher- order
three-body forces do not stabilize the face-centred-cubic lattice for argon,
the hexagonal-close-packed lattice having a slightly lower energy.
The chemistry of the DNA-p-Nitrophenylhydrazine reaction
Authors: Martin RF
Published: September 2010

The chemistry of the
reaction between DNA and pNPH has been investigated
by isolation and analysis of the chromogen. The perchlorate
of the cationic chromo-gen was prepared from the reineckate by anion exchange chromatography, and samples
from both DNA-pNPH and furfuryl
alcohol-pNPH reaction mixtures were found to have
identical i.r. and p.m.r.
spectra. The data obtained from the p.m.r. spectra
were consistent with a reaction scheme involving formation of a pyridazinium cation which subsequently yields the chromophore
on treatment with alkali.
The oxidation of potassium dixanthates to tetraxanthogens
Authors: Hunt MR , Winter G
Published: September 2010

Alkyl monoxanthates
are used extensively in sulphide ore flotation and there is an abundant
literature1 dealing with their chemistry and physical properties. Very little seems to be
known of dixanthates. The insertion of CS2
into the potassium salts of ethylene glycol, diethylene
glyool, and triethylene
glycol was reported by Shupe.Woods has shown recently
that oxidation of the ethyl xanthate ion to dixantho-gen
plays a major role in ore flotation processes when ethylxanthate is used as a
collector. The ease or otherwise of this oxidation and the nature of the
oxidation product is likely, therefore, to have a marked influence on the
efficiency of the process. A study of the oxidation of dixanthates
is the purpose of the present work.
Fungal metabolites. II. Synthesis of some 1,4-naphthoquinone derivatives
Authors: Coombe RG
Published: September 2010

The synthesis of
3-acetonyl-2-hydroxy-5,7- and -5,8-dimethoxy-l,4-naphtho quinone and their
2-methoxy derivatives is described.
Phonological decisions require both the left and right supramarginal gyri
Authors: Hartwigsen Gesa , Baumgaertner Annette , Price Cathy J. , Koehnke Maria , Ulmer Stephan , Siebner Hartwig R.
Published: September 2010

Recent functional imaging studies demonstrated that both the left and right supramarginal gyri (SMG) are activated when healthy right-handed subjects make phonological word decisions. However, lesion studies typically report difficulties with phonological processing after left rather than right hemisphere damage. Here, we used a unique dual-site transcranial magnetic stimulation (TMS) approach to test whether the SMG in the right hemisphere contributes to modality-independent (i.e., auditory and visual) phonological decisions. To test task-specificity, we compared the effect of real or sham TMS during phonological, semantic, and perceptual decisions. To test laterality and anatomical specificity, we compared the effect of TMS over the left, right, or bilateral SMG and angular gyri. The accuracy and reaction times of phonological decisions were selectively disrupted relative to semantic and perceptual decisions when real TMS was applied over the left, right, or bilateral SMG. These effects were not observed for TMS over the angular gyri. A follow-up experiment indicated that the threshold-intensity for inducing a disruptive effect on phonological decisions was identical for unilateral TMS over the right or left SMG. Taken together, these findings provide converging evidence that the right SMG contributes to accurate and efficient phonological decisions in the healthy brain, with no evidence that the left and right SMG can compensate for one another during TMS. Our findings motivate detailed studies of phonological processing in patients with acute or long-term damage of the right SMG.
A sample storage management system for biobanks
Authors: Voegele C. , Alteyrac L. , Caboux E. , Smans M. , Lesueur F. , Le Calvez-Kelm F. , Hainaut P.
Published: September 2010

Summary: Establishment of large-scale biobanks of human specimens is essential to conduct molecular pathological or epidemiological studies. This requires automation of procedures for specimen cataloguing and tracking through complex analytical processes. The International Agency for Research on Cancer (IARC) develops a large portfolio of studies broadly aimed at cancer prevention and including cohort, case–control and case-only studies in various parts of the world. This diversity of study designs, structure, annotations and specimen collections is extremely difficult to accommodate into a single sample management system (SMS). Current commercial or academic SMS are often restricted to a few sample types and tailored to a limited number of analytic workflows [Voegele et al. (2007) A laboratory information management system (LIMS) for a high throughput genetic platform aimed at candidate gene mutation screening. Bioinformatics, 23, 2504–2506].

Thus, we developed a system based on a three-tier architecture and relying on an Oracle database and an Oracle Forms web application. Data are imported through forms or csv files, and information retrieval is enabled via multi-criteria queries that can generate different types of reports including tables, Excel files, trees, pictures and graphs. The system is easy to install, flexible, expandable and implemented with a high degree of data security and confidentiality. Both the database and the interface have been modeled to be compatible with and adaptable to almost all types of biobanks.

Availability and implementation: The SMS source codes, which are under the GNU General Public License, and supplementary data are freely available at ‘http://www-gcs.iarc.fr/sms.php’

Supplementary information:  Supplementary data are available at Bioinformatics online.

Contact:  voegele@iarc.fr
Equipment Setup for Drosophila Electrophysiology
Authors: Zhang Bing , Stewart Bryan
Published: September 2010

INTRODUCTION

The Drosophila larval neuromuscular junction (NMJ) shares many structural and functional similarities to synapses in other animals, including humans. These include the basic feature of synaptic transmission, as well as the molecular mechanisms regulating the synaptic vesicle cycle. Because of its large size, easy accessibility, and the well-characterized genetics, the fly NMJ remains an excellent model system for dissecting the cellular and molecular mechanisms of synaptic transmission. This article describes the components of an electrophysiology setup, commonly referred to as an electrophysiology rig. The rig described here is based on equipment and software used in the Cold Spring Harbor Laboratory (CSHL) course “Neurobiology of Drosophila.”
Production of Foamy Virus Vector and Transduction of Hematopoietic Cells
Authors: Josephson Neil C. , Russell David W.
Published: September 2010

INTRODUCTION

Foamy viruses (FVs), or spumaviruses, are nonpathogenic retroviruses that have been developed as integrating viral vectors. This protocol presents methods for producing high-titer FV vector stocks, free of contaminating replication-competent retrovirus, to be used for transducing hematopoietic stem cells. FV vector stocks are produced by transfecting 293 cells, harvesting and filtering the culture medium, and concentrating vector virions by ultracentrifugation. The resulting stocks are free of replication-competent helper virus, as indicated by a sensitive marker rescue assay. A typical stock made from 23 10-cm dishes has a final volume of 2 mL with a titer of 107 to 108 transducing units/mL. Potential advantages of FV vectors include a lack of pathogenicity of the wild-type virus, a wide host range, stable virions that can be concentrated by centrifugation, a double-stranded DNA genome that is reverse-transcribed in the vector-producing cells, and the largest packaging capacity of any retrovirus. FV vectors are especially useful for transducing hematopoietic cells. Because hematopoietic stem cells have the ability to self-renew, proliferate, and repopulate the bone marrow after transplantation, efficient transduction of these cells offers the promise to cure many inherited and acquired diseases.
Solubilization of Escherichia coli Recombinant Proteins from Inclusion Bodies
Authors: Simpson Richard J.
Published: September 2010

INTRODUCTION

The high levels of expression produced by molecular cloning techniques make bacteria particularly useful for producing recombinant proteins. However, these proteins often are difficult to purify, owing to their tendency to aggregate and precipitate within the bacteria as insoluble inclusion bodies. Formation of inclusion bodies is especially common for nonbacterial proteins. Although no single method can be applied to every protein, a number of strategies are available to solubilize inclusion body proteins. This protocol describes one such method.
Focal Recording of Synaptic Currents from Single Boutons at the Drosophila Neuromuscular Junction
Authors: Zhang Bing , Stewart Bryan
Published: September 2010

INTRODUCTION

The Drosophila larval neuromuscular junction (NMJ) shares many structural and functional similarities to synapses in other animals, including humans. These include the basic feature of synaptic transmission, as well as the molecular mechanisms regulating the synaptic vesicle cycle. Because of its large size, easy accessibility, and the well-characterized genetics, the fly NMJ remains an excellent model system for dissecting the cellular and molecular mechanisms of synaptic transmission. Focal recording is an extracellular method designed for the study of synaptic activity of one or a few synaptic boutons rather than the ensemble activity of all of the boutons, as occurs with intracellular recording or the two-electrode voltage-clamp (TEVC) method. This is a useful technique for investigating the properties of different motor neurons that innervate the same muscle, applying statistical analysis to discrete synaptic events, and investigating the heterogeneity of synaptic release properties among boutons.
In Vivo Imaging of Cerebral Hemodynamics Using High-Frequency Micro-Ultrasound
Authors: Sun John , Lindvere Liis , van Raaij Martijn E. , Dorr Adrienne , Stefanovic Bojana , Foster F. Stuart
Published: September 2010

INTRODUCTION

Assessment of cerebral vascular response is important in neuroscience research. Some imaging modalities that are commonly used to detect flow and/or vessel diameter changes in the brain include magnetic resonance imaging, positron emission tomography, and optical intrinsic signal imaging. Ultrasound has not typically been used to assess neurovascular response but recent advances in the technology have led to the development of micro-ultrasound systems with significant potential for this application. The state of the art in high frequency (15-50 MHz) micro-ultrasound is based on linear arrays specifically designed for small animal imaging. These systems can achieve axial resolution ranging from 30 to 200 μm. They are capable of quantifying brain hemodynamics in terms of red blood cell (RBC) velocity, flow, and vascular density in real time, up to 35 mm below the cortical surface, and can achieve temporal resolution of up to 1000 frames per second. This protocol describes imaging of the rat brain using various ultrasound imaging modes (power Doppler, color Doppler, pulsed-wave Doppler, and nonlinear contrast-enhanced imaging) to assess the state of cerebral microcirculation.
Immediate versus delayed quitting and rates of relapse among smokers treated successfully with varenicline, bupropion SR or placebo
Authors: Gonzales David , Jorenby Douglas E. , Brandon Thomas H. , Arteaga Carmen , Lee Theodore C.
Published: September 2010

Aims  We assessed to what degree smokers who fail to quit on the target quit date (TQD) or lapse following TQD eventually achieve success with continued treatment.

Design  A secondary analysis of pooled data of successful quitters treated with varenicline (306 of 696), bupropion (199 of 671) and placebo (121 of 685) from two identically‐designed clinical trials of varenicline versus bupropion sustained‐release and placebo.

Setting  Multiple research centers in the US.

Participants  Adult smokers (n = 2052) randomized to 12 weeks drug treatment plus 40 weeks follow‐up.

Measurement  The primary end‐point for the trials was continuous abstinence for weeks 9–12. TQD was day 8. Two patterns of successful quitting were identified. Immediate quitters (IQs) were continuously abstinent for weeks 2–12. Delayed quitters (DQs) smoked during 1 or more weeks for weeks 2–8.

Findings  Cumulative continuous abstinence (IQs + DQs) increased for all treatments during weeks 3–8. Overall IQs and DQs for varenicline were (24%; 20%) versus bupropion (18.0%, P = 0.007; 11.6%, P < 0.001) or placebo (10.2%, P < 0.001; 7.5%, P < 0.001). However, DQs as a proportion of successful quitters was similar for all treatments (varenicline 45%; bupropion 39%; placebo 42%) and accounted for approximately one‐third of those remaining continuously abstinent for weeks 9–52. No gender differences were observed by quit pattern. Post‐treatment relapse was similar across groups.

Conclusions  Our data support continuing cessation treatments without interruption for smokers motivated to remain in the quitting process despite lack of success early in the treatment.
Smoothelin is a specific and robust marker for distinction of muscularis propria and muscularis mucosae in the gastrointestinal tract
Authors: Montani Matteo , Thiesler Thore , Kristiansen Glen
Published: September 2010

Montani M, Thiesler T & Kristiansen G (2010) Histopathology 57, 244–249

Smoothelin is a specific and robust marker for distinction of muscularis propria and muscularis mucosae in the gastrointestinal tract

Aims:  As tumour specimens and biopsy specimens become smaller, recognition of anatomical structures relevant for staging is increasingly challenging. So far no marker is known that reliably discriminates between muscularis propria (MP) and muscularis mucosae (MM) of the gastrointestinal tract. Recently, smoothelin expression has been shown to differ in MP and MM of the urinary bladder. We aimed to analyse the expression of smoothelin in the gastrointestinal tract in MP and MM in order to define a novel diagnostic tool to identify MM bundles.

Methods and results:  The expression of smoothelin was analysed immunohistochemically in comparison with α‐smooth muscle actin (α‐SMA) in specimens from colon, stomach and oesophagus (n = 107). In contrast to α‐SMA, which equally stained MM and MP, absent or significantly weaker smoothelin expression was found in MM was found, which was particularly valid in colon and gastric specimens.

Conclusions:  The combination of smoothelin and SMA represents a robust marker to discriminate MM from MP in the gastrointestinal tract.
Histological grading of breast cancer on needle core biopsy: the role of immunohistochemical assessment of proliferation
Authors: Kwok T’ng Chang , Rakha Emad A , Lee Andrew H S , Grainge Matthew , Green Andrew R , Ellis Ian O , Powe Desmond G
Published: September 2010

Kwok T C, Rakha E A, Lee A H S, Grainge M, Green A R, Ellis I O & Powe D G (2010) Histopathology57, 212–219

Histological grading of breast cancer on needle core biopsy: the role of immunohistochemical assessment of proliferation

Aims:  Histological grade assessed on needle core biopsy (NCB) moderately concurs with the grade in the surgical excision specimen (SES) (κ‐values between 0.35 and 0.65). A major cause of the discrepancy is underestimation of mitoses in the NCB specimen. The aim was to determine the best method of assessing proliferation on NCB.

Methods and results:  Proliferative activity of 101 invasive carcinomas of the breast on NCB and SES was assessed using mitotic counts on routine haematoxylin and eosin (H&E) sections and immunohistochemical markers Mib‐1 and phosphorylated histone H3 (PPH3). H&E mitotic count in SES was considered as the gold standard. H&E mitotic count was found to be underestimated on NCB when compared with that in SES (P < 0.001), but no significant difference was detected between NCB and SES regarding Mib‐1 (P = 0.13) or PPH3 (P = 0.073). Using receiver–operating characteristic curve, Mib‐1 on NCB was found to agree with the gold standard significantly better than routine H&E on NCB.

Conclusions:  Immunohistochemical markers in NCB showed better concordance with H&E mitotic count in SES (gold standard) than routine H&E mitotic count in NCB. Further refinement of cut‐offs and scoring methods is needed.
Expression of Bcl‐2 family proteins and association with clinicopathological characteristics of oral squamous cell carcinoma
Authors: Coutinho‐Camillo Cláudia Malheiros , Lourenço Silvia Vanessa , Nishimoto Ines Nobuko , Kowalski Luiz Paulo , Soares Fernando Augusto
Published: September 2010

Coutinho‐Camillo C M, Lourenço S V, Nishimoto I N, Kowalski L P & Soares F A (2010) Histopathology57, 304–316

Expression of Bcl‐2 family proteins and association with clinicopathological characteristics of oral squamous cell carcinoma

Aims:  To characterize the expression of proteins that inhibit (Bcl‐2, Bcl‐x, Bcl‐xL, Bcl‐2‐related protein A1, BAG‐1) or promote (Bak, Bax, Bim/Bod, Bim‐Long, Bad, Bid, PUMA) apoptosis and determine possible correlations between the expression of these proteins and clinicopathological features of oral squamous cell carcinoma (OSCC).

Methods and results:  Two‐hundred and twenty‐nine cases of OSCC, arranged in a tissue microarray, were immunohistochemically analysed. The results demonstrated that the absence of vascular invasion was associated with increased expression of Bak, Bax, Bcl‐xL, Bcl‐2‐related protein and PUMA. Increased expression of Bim/Bod and BAG‐1 was associated with the presence of perineural infiltration. An increase in Bid and Bim‐Long expression was associated with moderately to well‐differentiated tumours. Increased expression of the Bcl‐2‐related protein and PUMA was associated with tumours occurring in the floor of mouth and increased expression of PUMA was also associated with recurrence of the tumour. Multivariate Cox analysis demonstrated that PUMA and Bim‐Long were independent factors in prognosis of OSCC.

Conclusions:  Our results showed the involvement of the Bcl‐2 family of proteins in OSCC tumorigenesis and suggest that the expression of apoptotic molecules might be used as a prognostic indicator for OSCC.
Specificity of DOG1 (K9 clone) and protein kinase C theta (clone 27) as immunohistochemical markers of gastrointestinal stromal tumour
Authors: Wong Newton A C S , Shelley‐Fraser Golda
Published: September 2010

Wong N A C S & Shelley‐Fraser G (2010) Histopathology 57, 250–258

Specificity of DOG1 (K9 clone) and protein kinase C theta (clone 27) as immunohistochemical markers of gastrointestinal stromal tumour

Aims:  DOG1 and protein kinase C (PKC) theta are both sensitive immunohistochemical markers of gastrointestinal stromal tumour (GIST). However, there are conflicting data regarding the specificity of the most commonly used PKC theta antibody (clone 27), and there are no existing data regarding the specificity of the only known commercially available DOG1 antibody (K9 clone) at the time of writing. This study’s aim was to characterize the immunoreactivity patterns of both monoclonal antibodies amongst a wide range of neoplasm types including, in particular, histological mimics of GIST.

Methods and results:  Immunohistochemistry for DOG1 and PKC theta was performed on whole tissue sections from 23 different neoplasm types (total of 125 cases). Ten of these neoplasm types showed CD117 immunopositivity. Only three (Ewing’s sarcoma, glomus tumour and synovial sarcoma) of the 23 neoplasm types showed DOG1 immunopositivity, and such positivity was often focal and weak in intensity. In contrast, all but four (ganglioneuromas, leiomyomas, desmoplastic small round cell tumours and PEComa/angiomyolipomas) of the 23 neoplasm types showed PKC theta immunopositivity.

Conclusions:  Compared with CD117, DOG1 (using the K9 antibody) is a more specific marker, whereas PKC theta (using the clone 27 antibody) is a considerably less specific immunohistochemical marker for GIST.
DOG1 and CD117 are the antibodies of choice in the diagnosis of gastrointestinal stromal tumours
Authors: Novelli Marco , Rossi Sabrina , Rodriguez‐Justo Manuel , Taniere Philippe , Seddon Beatrice , Toffolatti Luisa , Sartor Chiara , Hogendoorn Pancras C W , Sciot Raf , Van Glabbeke Martine , Verweij Jaap , Blay Jean Yves , Hohenberger Peter , Flanagan Adrienne , Dei Tos Angelo P
Published: September 2010

Novelli M, Rossi S, Rodriguez‐Justo M, Taniere P, Seddon B, Toffolatti L, Sartor C, Hogendoorn P C W, Sciot R, Van Glabbeke M, Verweij J, Blay J Y, Hohenberger P, Flanagan A & Dei Tos A P (2010) Histopathology57, 259–270 DOG1 and CD117 are the antibodies of choice in the diagnosis of gastrointestinal stromal tumours

Aims:  The histopathological diagnosis of gastrointestinal stromal tumours (GIST) is typically made based on a combination of clinical and morphological features supported by immunohistochemistry studies. The aim of this study was to examine the staining quality, sensitivity, specificity and utility of antibodies used commonly in GIST diagnosis.

Methods and results:  Immunohistochemistry with a panel of antibodies [CD117, DOG1, protein kinase C (PKC)‐theta, nestin, CD34, smooth muscle actin (SMA), desmin, S100 and CD171] was performed on whole sections from 187 GIST and 29 gastrointestinal mesenchymal tumours, and on several microarrays including 355 GISTs and 120 soft tissue sarcomas. Results showed that DOG1 and CD117 were the most sensitive and specific antibodies used in GIST diagnosis. PKC‐theta and nestin were sensitive, but less specific, also staining other spindle cell tumours commonly considered in the differential diagnosis of GIST. CD34 staining was less sensitive than many of the other antibodies and of limited aid in diagnosis. The smooth muscle markers SMA and desmin, together with the neural marker S100, were unhelpful in confirming a diagnosis of GIST, but were particularly useful in the exclusion/diagnosis of other gastrointestinal mesenchymal tumour types.

Conclusions:  In the majority of histologically suspected GISTs a combination of CD117 and DOG1 immunostaining is sufficient to confirm the histological diagnosis.