Objectives: Manufacturing and spraying workers of organophosphate pesticides (OPs) could suffer from testicular spermogenesis and steroidogesis dysfunctions particularly when their degradation is subnormal. Aim: Exploration of spermatogenic and endocrinologic testicular functions and paraoxonase/arylesterase (PON1/ARY) degrading activities of the organophosphate parathion and its oxon in their ...

In this paper, we reported the construction of a hybrid biosensor for direct, highly selective, sensitive, and rapid quantitative determination of organophosphate pesticides with p-nitrophenyl substituent using purified organophosphorus hydrolase (OPH) for the initial hydrolysis and Arthrobacter sp. JS443 for subsequent p-nitrophenol oxidation. The biocatalytic layer was prepared by co-immobili...

Psychrophilic bacteria, which grow on lactose as a carbon source, were isolated from Antarctic polar sea water. Among the psychrophilic bacteria isolated, strain KNOUC808 was able to grow on lactose at below 5°C, and showed 0.867 unit of o-nitrophenyl β-D-galactopyranoside(ONPG) hydrolyzing activity at 4°C. The isolate was gram-negative, rod, aerobic, catalase positive and oxidase positive. Opt...

The rapid destruction of chemical threats, such as phosphate-based nerve agents, is of considerable current interest. The hydrolysis of the nerve-agent simulant methylparaoxon, as catalyzed by UiO-66 and UiO-67, was examined as a function of pH. Surprisingly, even though typical phosphate−ester hydrolysis mechanisms entail nucleophilic attack of the simulant by aqueous hydroxide, the rate of hy...

The presence of a p-nitrophenyl group converts acetone into an excellent and versatile nucleophile in organocatalytic processes, able to react with α,β-unsaturated aldehydes affording β-substituted α-arylcyclohexenones via a Michael reaction/aldol reaction/dehydration sequence, which occurs in good yields, ee up to 96% and complete diastereoselectivity. The resulting compounds are excellent syn...

The in vitro mutagenic activation of N-hydroxy-2-acetylaminofluorene (N-OH-AAF) in the Salmonella test system (strain TA 1538) by isolated rat and mouse liver cell nuclei and the in vitro covalent binding of N-OH-AAF to nuclear nucleic acids and proteins were studied. Mutagenic acti vation of N-OH-AAF and 2-acetylaminofluorene by liver cell nuclei from both rat and mouse was observed. The mutag...

objective: organophosphorus hydrolase (oph) is a homodimeric enzyme that can hydrolyze phosphoester bonds and reduce the toxicity of organophosphorus compounds. this makes oph a suitable element for the biodegradation of these compounds. methods: we successfully cloned the oph gene from pseudomonas diminuta, after optimization for pichia pastoris, into a yeast expression vector (ppiczαb). afte...

The classical laboratory tests for exposure to organophosphorus toxicants (OP) are inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in blood. In a search for new biomarkers of OP exposure, we treated mice with a biotinylated organophosphorus agent, FP-biotin. The biotinylated proteins in muscle were purified by binding to avidin-Sepharose, separated by gel ele...

Urinary N-hydroxy metabolites of the bladder carcinogens, 2-aminofluorene and 4-aminobiphenyl, were examined for the induction of unscheduled DNA synthesis (UDS) in urothelial cells of several susceptible species. N-Hydroxy-2-aminofluorene, N-hydroxy-2-acetylaminofluorene (N-OH-AAF), N-hydroxy-4-aminobiphenyl, N-hydroxy-4-acetylaminobiphenyl, and the N-glucuronides of these two hydroxylamines i...