Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The metabolic pathways of p-nitroanisole, 4-nitro-m-cresol and methyl parathion in Malaysian prawns (Macrobrachium rosenbergii), ridgeback prawns (Sicyonia ingentis) and crayfish (Procambarus clarkii) were compared. 2. The Malaysian prawns and ridgeback prawns were shown to O-demethylate 29% and 11%, respectively, of an accumulated level of p-nitroanisole, while crayfish were able to O-demethylate 98% of the accumulated level of nitroanisole. 4-Nitro-m-cresol oxidation was not detected in either prawn species. In contrast, 5-hydroxy-2-nitrobenzaldehyde was the major metabolite formed from nitrocresol metabolism by crayfish. 3. Both prawn species readily dearylated methyl parathion to form p-nitrophenol and p-nitrophenyl conjugates. Crayfish displayed a similar trend in methyl parathion metabolism. 4. Nitroreduction was observed in the metabolism of 4-nitro-m-cresol by ridgeback prawns, which excreted 4-nitroso-m-cresol as a minor product. Reduction products were not observed in the metabolism of the three substrates by Malaysian prawns or crayfish. 5. Conjugation was overall the dominant detoxication pathway observed in the decapods. Malaysian prawns conjugated p-nitrophenol and 4-nitro-m-cresol to form the corresponding beta-D-glucosides and sulphate monoesters. Ridgeback prawns formed beta-D-glucosides in small quantities, preferring conjugation of p-nitrophenol and 4-nitro-m-cresol to form sulphates and unknown conjugates through a unique conjugation pathway. Crayfish conjugated the phenolic substrates to form exclusively the beta-glucosides. 6. The unknown conjugates formed by ridgeback prawns had chromatographic properties similar to the corresponding beta-D-glucosides but were refractory to the deconjugation by alpha- or beta-glucosidase, beta-galactosidase, aryl sulphatase and beta-glucuronidase. Phenolic conjugation ability appeared to follow the order of ridgeback prawns greater than Malaysian prawns greater than crayfish.
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PMID:Comparative metabolism of nitroaromatic compounds in freshwater, brackish water and marine decapod crustaceans. 343 90

A gas chromatographic method for the analysis of cresol metabolites of toluene and [2H8]toluene in urine was developed. Cresol glucuronides and sulfates in urine were hydrolyzed with beta-glucuronidase and arylsulfatase. Following extraction with tert.-butyl methyl ether and solvent exchange into benzene, the cresols were derivatized with heptafluorobutyric anhydride to form the heptafluorobutyrate esters. The derivatives were analyzed by gas chromatography with electron capture detection. Chromatographic resolution was achieved between all cresol isomers and their 2H7 analogs. Calibration ranged from 0.001 to 500 microg/ml. Recoveries were 55-97% and showed no trend with respect to analyte concentration. Within-day precision of analyses of benchmark urine samples had a coefficient of variation of less than 4%. The assay sensitivity was limited by chromatographic background but was sufficient for quantification of the unlabeled cresols in urine from men with only environmental exposure to toluene. Average levels in urine samples from 45 men were 0.023, 0.054 and 37 microg/ml for o-, m- and p-cresol, respectively.
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PMID:Quantitation of o-, m- and p-cresol and deuterated analogs in human urine by gas chromatography with electron capture detection. 944 67

We investigated kinetics of p-cresol, m-cresol, and their glucuronide and sulfate metabolites in blood and organs of rats. We established a quantitative analysis method for the measurement of the concentrations of cresols. Endogenous beta-glucuronidase, an enzyme which hydrolyses the glucuronide, existed in rat organs, and it influenced the procedures for cresol hydrolysis of sulfatase. It was necessary for the quantitative analysis of cresol sulfate in organs to add the saccharolactone (d-saccharic acid 1,4-lactone) as an inhibitor for beta-glucuronidase. On the other hand, endogenous sulfatase did not interfere in the quantitative analysis of the glucuronide. It was found that cresol administered via the stomach tube diffuses directly through gastric and small intestinal walls because the unconjugate cresol concentrations were extremely high not only in the liver, but also in the spleen. The unconjugates of cresol in the liver, spleen and kidney were detected in high concentrations even when the unconjugates were not detected in the blood. m-Cresol was easily metabolized to sulfate, and the p-cresol to glucuronide in rats. The concentration ratios of m-cresol to p-cresol in blood and organs were different from the rate of the cresol soap solution that was administered. The pharmacokinetics was different between p-cresol and m-cresol in rats.
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PMID:Quantitative analysis of cresol and its metabolites in biological materials and distribution in rats after oral administration. 1517 71