Theoretical molecular descriptors relevant to the uptake of persistent organic pollutants from soil by zucchini. A QSAR study.

The uptake of persistent organic pollutants (POPs) from soil by plants allows the development of phytoremediation protocols to rehabilitate contaminated areas. The use of diverse theoretical descriptors has been reported in the literature for developing quantitative structure-activity relationship (QSAR) models for predicting the bioconcentration factors (BCFs) of POPs in different plants. In this paper an evaluation is given on the molecular properties of POPs in terms of theoretical molecular descriptors that are relevant to the uptake and accumulation of these persistent pollutants from soil by two zucchini varieties.

Interpretation of scoring functions using 3D molecular fields. Mapping the diacyl-hydrazine-binding pocket of an insect ecdysone receptor.

A method is presented for the interpretation of receptor docking score values (rough measures of binding affinities) of ligands in terms of 3D molecular field interaction contributions. The FlexX and FlexX-Pharm methods were used to dock the structures of designed sets of ligands into the ligand-binding pocket of a selected receptor. In the next step the relationship was investigated between the FlexX and CScore scores and 3D molecular fields obtained for the docked conformations of the ligands, using the CoMFA (Comparative Molecular Field Analysis) and CoMSIA (Comparative Molecular Similarity Indices Analysis) methods.

Effects of anti-ecdysteroid quaternary derivatives of azole analogues of metyrapone on the post-embryonic development of the red cotton bug (Dysdercus cingulatus F).

In order to improve the larvicidal activity of the azole analogues of metyrapone, previously found to have a strong inhibitory activity on ecdysone 20-monooxygenase (E-20-M) from the fleshfly Neobellieria bullata Parker, soft-alkylated compounds (3-(1,1-dimethyl-2-oxo-2-phenylethyl)-1-dodecanoyloxymethyl-1H-imidazolium chloride, sPIM) and (1-(1,1-dimethyl-2-oxo-2-phenylethyl)-4-dodecanoyloxymethyl-1H-1,2,4-triazolium chloride, sPTM), derivatives of phenyl-imidazolyl-metyrapone (PIM) and phenyl-1,2,4-triazolyl-metyrapone (PTM), respectively, were synthesized. Both sPIM and sPTM, designed as propesticides, inhibited E-20-M in vitro at 10(-4) M concentration, which was unexpected since they had been expected to be inactive in vitro and to gain activity only within the organism. sPTM significantly delayed the pupariation of N.

11beta-Hydroxysteroid dehydrogenase type 1: tissue-specific expression and reductive metabolism of some anti-insect agent azole analogues of metyrapone.

The azole analogues of metyrapone are novel candidates for selective anti-insect agents that inhibit the synthesis of 20-hydroxyecdysone (20E), the moulting hormone of insects. Metyrapone, which is a model substrate for studying the reductive properties of oxidoreductases, is itself effectively reduced to the corresponding alcohol by the enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD 1). For this reason, the ability of 11beta-HSD 1 to metabolize the metyrapone analogues as well was studied.

Carbonyl reduction of an anti-insect agent imidazole analogue of metyrapone in soil bacteria, invertebrate and vertebrate species.

Carbonyl reduction to the respective alcohol metabolites of the anti-insect agent imidazole analogue of metyrapone, NKI 42255 (2-(1-imidazolyl)-1-(4-methoxyphenyl)-2-methyl-1-propanone) and its parent compound metyrapone was characterized in subcellular fractions previously described bacterial and mammalian hydroxysteroid dehydrogenases/carbonyl from soil bacteria, as well as insect, invertebrate and teleost species. The enzymes involved in this metabolic step were characterized with respect to their cosubstrate specificities, inhibitor susceptibilities, and immunological crossreactivities with antibodies directed against reductases (HSD/CR). All fractions investigated rapidly reduced metyrapone, with highest specific activities found in insect, invertebrate and vertebrate fractions.