In the present study it is demonstrated that MO-QSARs (quantitative structure activity relationships based on calculated molecular orbital substrate characteristics) of cytochrome P450-catalysed biotransformation of benzene derivatives obtained in previous studies for Wistar rats, can be extrapolated to other species, including man. First, it was demonstrated that the regioselectivity of the in...

Since the first zirconacyclopentadiene was prepared by coupling of 2 equiv of diphenylacetylene on zirconocene in 1970 [1], many groups have reported the formation of zirconacyclopentadienes [1]. Surprisingly, for more than 20 years almost no carbon–carbon bond formation reactions have been reported for zirconacyclopentadienes. Only one paper appeared in 1983 to show the insertion reaction of t...

P.sub.2][O.sub.5]/[H.sub.3]P[O.sub.4] (PPA) was found to be an efficient new reagent for probing the mechanism of acylation reactions and Fries rearrangement of acyloxy benzene derivatives and also the direct acylation reactions of phenol derivatives with Carboxylic acids. The reactions proceeded smoothly in the presence of PPA and are highly selective for the preparation of the ortho isomers o...

This paper presents a novel and effective genetic algorithm approach for generating computational models for hazard assessment. With millions of proposed chemicals being registered each year, it is impossible to come even remotely close to completing the battery of tests needed for the proper understanding of the toxic effects of these chemicals. Computer models can give quick, cheap, and envir...

The synthesis and applications of the first water-soluble benzene derivative bearing a set of three different and orthogonal bioconjugatable groups (aminooxy, azido and thiol) are described. The combined use of a 5-amino isophthalic acid scaffold and unusual acid-labile protecting groups for temporarily masking aminooxy and thiol moieties has enabled the development of a highly convergent appro...

Self-organized maps (SOM) have been applied to analyze the similarities of chemical compounds and to select from a given pool of descriptors the smallest and more relevant subset needed to build robust QSAR models based on fuzzy ARTMAP. First, the category maps for each molecular descriptor and for the target activity variable were created with SOM and then classified on the basis of topology a...

The title chiral photochromic Schiff base compound, C21H18BrN3O, was synthesized from (R)-(+)-1-(4-bromo-phen-yl)ethyl-amine and the salicyl-aldehyde of an azo-benzene derivative. The mol-ecule corresponds to the phenol-imine tautomer, the C=N and N-C bond distances being 1.285 (3) and 1.470 (3) Å, respectively. The diazenyl group adopts a trans form, with an N=N distance of 1.256 (3) Å. The hy...

The volatile composition of 20-year-old out-of-service creosote-treated railway wood sleepers was studied. The emitted volatile fraction was collected by means of dynamic purge-and-trap concentration at ambient temperature, and analyzed by comprehensive two-dimensional gas chromatography (GC x GC) hyphenated with mass spectrometric detection systems, using quadrupole (GC x GC/qMS) and time-of-f...

Adsorption of benzene derivatives of various chemical properties from dilute aqueous solutions on the Norit activated carbons is investigated. The experimental systems are analyzed in terms of adsorption theory on energetically heterogeneous solids. The relations between the optimization isotherm parameters, i.e. equilibrium constants and heterogeneity parameters, and the solute properties, e.g...

The direct electrophilic no-carrier-added (n.c.a.) aromatic radioiodination was examined using various metal salts in trifluoroacetic acid (TFA) as in situ oxidation agents. Two different types of metal salts were used comprising TFAsoluble (Pb(CH3CO2)4, Mn(CH3CO2)3, KMnO4, Tl(CF3CO2)3, AgCF3SO3) and TFA-insoluble (Ce(CF3SO3)4, RuCl3, FeBr3, K2Cr2O7) salts. Optimization of both labelling system...