The machine learning program GOLEM from the field of inductive logic programming was applied to the drug design problem of modeling structure-activity relationships. The training data for the program were 44 trimethoprim analogues and their observed inhibition of Escherichia coli dihydrofolate reductase. A further 11 compounds were used as unseen test data. GOLEM obtained rules that were statis...

New 2-phenylpyridazinones, analogs o f 4-chloro-5-methylamino-2-phenylpyridazin-3(2H)ones, were assayed for their phytotoxic activity to interfere with plant pigment formation. Six derivatives with — SCF3, — OCF2CH FCF3, — O CH F2, — CN, or — Br in meta position o f the phenyl ring exhibited similar or better bleaching activity than the m -CF3 analog (norflurazon). The activity is predominantly...

Diphenylamines, Inhibitors, Photosynthetic Electron Transport A number of 16 substituted diphenylamines have been tested for their inhibitory activity on photosynthetic NADP reduction and photophosphorylation. The most active compounds exhibited p l50 values of 6.0 in photosynthetic electron transport and 6.8 in cyclic photophosphorylation, respectively. The inhibition site in electron flow of ...

Structure-property correlation uses the occurrence of specific structural features within chemical molecules in statistical analyses. The features are correlated with physicochemical properties or biological activities. Quantitative structure-activity relationships (QSAR) have been predominantly applied to the design of drugs (see Ariens, 1971) and to the understanding of drug disposition (Lien...

An HPLC assay is described that can be used to study the covalent bonding interaction of carbinolamine-containing pyrrolo[2,1-c][1,4]benzodiazepines with the model nucleophile thiophenol, in order to evaluate electrophilicity at the C-11-position. Preliminary experiments with anthramycin, tomaymycin and neothramycin show that their reaction with thiophenol follows second-order kinetics, but the...

In an attempt to relate the hallucinogenic potencies in man of some biologically important amphetamines and phenethylamines, the 1-octanol-water partition coefficients for 11 amphetamines were determined. Using these values and published Hansch pi constants, the log P for 17 additional amines was estimated. It was found that lipophilicity, as measured by the log of the partition coefficient, ma...

The cyclooxygenase-2 enzyme inhibition activity of 5-aryl-2,2-dialkyl-4-phenyl-3(2H)furanone derivatives is quantitatively analyzed through Fujita-Ban and Hansch type of approaches. The analyses have helped to ascertain the role of different substituents in explaining the observed inhibitory activity of these congeners. From both approaches it is revealed that more hydrophobic susbtituents at 4...

CNDO/2 calculations have been performed on a series of alkyl, alkoxy, and alkylthio derivatives of phenethylamine and phenylisopropylamine. The results of these, of van der Waals volume calculations, and of Hansch type hydrophobicity calculations were correlated with psychotomimetic activity by chemometric methods. Eight parameters, involving seven chemical descriptors, were found to be highly ...