Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Secondary cultures of hamster embryo cells exposed to 0.5 nmol [G-3H]7,12-dimethylbenz(a)anthracene (DMBA) per ml medium metabolized more than 90% of the DMBA within 48 hr. Samples of medium were extracted with chloroform, methanol, and water. The chloroform phases contained about one-third of the DMBA metabolites; the major chloroform-extractable metabolite was 8,9-dihydro-8,9-dihydroxy-7,12-dimethylbenz(a)anthracene. Beta-glucuronidase treatment of the aqueous methanol-soluble metabolites converted almost one-half of them to chloroform-soluble metabolites, of which more than 80% were identified as phenolic derivatives of DMBA. Similar metabolite profiles were obtained by treating the medium with beta-glucuronidase before chloroform extraction. Separation of the methyl group-hydroxylated derivatives of DMBA from the phenolic derivatives was accomplished by high-pressure liquid chromatography. Small amounts of hydroxymethyl derivatives were detected only in the chloroform-extractable material, whereas DMBA phenols were the major component of the beta-glucuronidase-released mateirla. These results indicate that the major pathway of DMBA metabolism in hamster embryo cells is oxidation of the aromatic rings and not oxidation of the methyl groups.
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PMID:Formation of glucuronic acid conjugates of 7,12-dimethylbenz(a)anthracene phenols in 7,12-dimethylbenz(a)anthracene-treated hamster embryo cell cultures. 9 31

Metabolites of 3'-methyl-4-(dimethylamino)azobenzene (3'-Me-DAB) in the rat bile and urine were investigated by the use of a tracer technique. 3H-3'-Me-DAB in cottonseed oil was administered orally by a stomach tube. The dye metabolites in the bile and urine collected during 24 hr after the administration were hydrolyzed with beta-glucuronidase/arylsulfatase. The hydrolyzed metabolites were then extracted with chloroform or separated by chromatography on Amberlite XAD-2 using methanol as a solvent. The metabolites in the chloroform or methanol eluates were identified by the reverse isotope dilution analysis, before or after separation by thin-layer chromatography. The N-demethylated, aryl hydroxylated, and their azo-reduced products were detected in the bile, in addition to the products oxidized at the ring methyl group as the new metabolites. On the other hand, the metabolites retaining the azo-linkage were scarcely detected in urine and instead 3-aminobenzoic acid, 3-amino-6-hydroxytoluene, and their N-acetylated products were major metabolites in urine. These results indicate that the metabolism of 3'-Me-DAB in the rat involves oxidation of the ring methyl group. Significance of the ring methyl group in the carcinogenic action of aminoazo dyes is also discussed.
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PMID:Analysis of biliary and urinary metabolites of 3'-methyl-4-(dimethylamino)azobenzene in rats. 10 70

A method for the separation of serum conjugated steroids, sulfates and glucuronides, is described. It is based on the fact that methylene blue forms complexes with ester-sulfates which can be quantitatively and specifically extracted by chloroform from aqueous phase. The quantitative determination of the conjugated fractions thus obtained can be done after solvolysis followed by hydrolysis by beta-glucuronidase from Helix pomatia.
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PMID:[Method of rapid separation of free, sulfoconjugated and glucuronoconjugated fractions of plasma steroids]. 12 37

[14C] Cholesterol-5 alpha, 6 alpha-expoxide, administered to mice by either gastric intubation or skin painting, was rapidly and primarily excreted in the feces. Residual amonts of the epoxide and its metabolites were found in a wide variety of organs, and persisted for at least 72 hr. At some sites (principally the liver, the small intestinal contents and the combined stomach/duodenum and their contents), the labeled compound existed in a water-soluble form which could not be extracted with chloroform/methanol. Treatment of the small intestinal contents with a preparation of beta-glucuronidase/sulfatase produced a marked increase in the amount of organic-solvent-extractable cholesterol-alpha-epoxide and other polar metabolites. Unchanged epoxide was found mainly in the feces and the skin at the site of application. On the basis of these results, stool specimens, and not blood samples, should be analyzed to detect the presence of this compound and/or its metabolites in vivo.
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PMID:The metabolic fate of cholesterol-5 alpha, 6 alpha-expoxide in vivo. 48 Nov 35

10 excretory products of Clofedanol (1-(o-chlorphenyl)-1-phenyl-3-dimethylaminopropanol) were identified in human urine. The following five products were extracted with chloroform at pH 1--2: o-(chlorphenyl)-phenylmethane (I), benzophenone (II), o-chlorbenzophenone (III), benzhydrol (IV), and o-(chlorphenyl)-beta-phenylacrolein (V). Two compounds were extracted with chloroform at pH 13--14: unchanged Clofedanol and 1-(o-chlorphenyl)-1-phenyl-3-dimethylaminopropene-1 (VI). N,N-dimethylamino-acetic acid (VII) was also identified in urine. Clofedanol and metabolite IV were present as free compounds, and they were also found after hydrolysis of metabolites VIII and IX with beta-glucuronidase.
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PMID:[Isolation and identification of some metabolites of clofedanol from human urine (author's transl]. 60 21

A mixture of [19-3H]hydroxyandrostenedione and [14C]androstenedione was administered intravenously to 3 women and urine was collected. Only negligible radioactivity could be extracted from the untreated urine. Most of the 14C but only 11% of the 3H was rendered solube in organic solvents by beta-glucuronidase. [3H-19]hydroxyandrostenedione was recovered from this fraction. The conjugates remaining in the urine were extracted into CHCl3 as their pyridinium salts. After solvolysis of the extract with HCLO4 in tetrahydrofuran, neutral metabolites were obtained. Substances extractable from water with organic solvents were obtained by solvolysis of the conjugates with perchloric acid in tetrahydrofuran. [3H-19]hydroxyandrostenedione was identified by isotopic dilution as the major product of solvolysis. Thus, 19-hydroxyandrostenedione undergoes conjugation with glucuronic acid and probably sulfuric acid, most likely at C-19. The major urinary metabolite is the sulfate-like conjugate. Reduction in ring A is less important than for other steroids.
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PMID:Metabolism of 19-hydroxyandrostenedione in human subjects. Urinary excretion of conjugates. 75 31

The metabolism of a new antisecretory and antiulcer drug, trithiozine (I.S.F. 2001, T), was studied in 4 hr rat urine samples after i.p. administration. After extraction at pH 7 with chloroform, the urine was either incubated with beta-glucuronidase or acidified to pH 2 and subsequently extracted with chloroform. The organic layers were evaporated to dryness and the residues used for TLC analysis. The neutral extracts revealed five spots, not present in control rat urine, corresponding to the unchanged drug T and to four metabolites. Two of the metabolites had been previously identified as the 4-(3,4,5-trimethoxybenzoyl)tetrahydro-1,4-oxazine (TBO) and the 4-(3,4,5-trimethoxythiobenzoyl)tetrahydro-1,4-oxazine-S-oxide (TO). Three other metabolites were found in the extracts after beta-glucuronidase incubation. TLC, U.V. and M.S. data were consistent with the structure 4-(3,5-dimethoxy-4-hydroxythiobenzoyl)tetrahydro-1,4-oxazine (HT), the corresponding S-oxide (HO) and the 4-(3,5-dimethoxy-4-hydroxybenzoyl)tetrahydro-1,4-oxazine (HBO). The acidic extracts revealed two spots structurally identified as the 3,4,5-trimethoxybenzoic acid (TBA) and the previous HBO. On the basis of present knowledge, a possible metabolic pathway of T is reported, consisting in a rapid metabolic oxidation on the sulfur atom and a slower demethylation on the para methoxy group. The presence of TBA is indicative of subsequent enzymatic hydrolysis of TBO. The intense and long-lasting inhibitory effect of T on gastric secretion is tentatively correlated with the pharmacological activities of some of its metabolites.
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PMID:Biotransformation of trithiozine. III - Isolation and identification of further metabolites in rat urine. 90 59

A method for the detection of nanogram quantities of nylidrin in human urine is described. The method involves beta-glucuronidase hydrolysis, extraction with chloroform, derivatization by silylation, and GLC determination. The suitability of the method was tested by analysis of urine samples of subjects after oral ingestion of nylidrin hydrochloride.
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PMID:GLC determination of nylidrin in human urine samples. 96 53

Four patients with a biliary fistula received 0.5 mg 3H-methylproscillaridin as a single oral dose. 55% of the dose was excreted in bile, 16% in urine and 3% in faeces. More than 60% of the radioactivity excreted in bile and urine appeared within the first 24 hours. 78% of the radioactivity in bile consisted of CHCl3-insoluble metabolites of methylproscillaridin, incubation of which with beta-glucuronidase led to splitting off glucuronic acid from almost 80%. Methylproscillaridin can be regarded as the principal conjugated compound. TLC-separation of CHCl3-soluble compounds from bile showed identical running of radioactivity with methylproscillaridin, proscillaridin and scillarenin and three unknown metabolites P1, P2, and P3. In urine the CHCl3-soluble fraction averaged 16% to 34% of the total amount and was identified as methylproscillaridin, proscillaridin, scillarenin, P2 and P3. The relative composition of the total radioactivity in faeces amounted to 77% methylproscillardidin, 4% scillarenin and 12% polar metabolites.
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PMID:Excretion of methylproscillaridin in patients with a biliary fistula. 123 71

1. Metabolites and DNA adducts of 3H-benzo(a)pyrene (BaP) formed by isolated hepatocytes from English sole (Parophrys vetulus) in vitro were compared to those in bile and liver of sole exposed i.m. to 3H-BaP. 2. English sole liver was perfused with a collagenase solution and hepatocytes were isolated with greater than 95% viability. Determination of kinetic parameters for metabolism of 3H-BaP showed a Km of 29 +/- 10 microM and an apparent Vmax of 1300 pmol BaP metabolized/10(6) cells per h. 3. Analysis of medium from hepatocyte cultures and bile by ion-pair h.p.l.c. showed significant amounts of radioactivity in regions where glucuronide and glutathione conjugates of BaP metabolites elute. No sulphate conjugates of BaP metabolites were detected. The major unconjugated metabolite formed by hepatocytes was the BaP-9,10-dihydrodiol. 4. Hydrolysis of glucuronide conjugates by beta-glucuronidase and reversed-phase h.p.l.c. analysis of chloroform-soluble metabolites showed the presence of BaP-7,8-dihydrodiol, 1-hydroxyBaP and 3-hydroxyBaP. The identities of these metabolites were confirmed by comparing their fluorescence spectra with those of standard BaP metabolites. 5. Analysis by 32P-postlabelling of the BaP-DNA adducts formed in isolated hepatocytes and liver revealed that major adducts detected are derived from the anti-7,8-dihydrodiol-9,10-epoxideBaP (anti-BaPDE) and syn-BaPDE. 6. Results show that the types of conjugated metabolites and BaP-DNA adducts formed in primary hepatocyte culture were similar to those in bile and liver of English sole exposed to BaP. Thus, isolated hepatocytes from English sole afford a reliable alternative to live fish for studies of the mechanisms of hepatic xenobiotic metabolism and DNA adduct formation in a species shown to be susceptible to induction of hepatocarcinogenesis by PAHs.
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PMID:The metabolism of benzo(a)pyrene by English sole (Parophrys vetulus): comparison between isolated hepatocytes in vitro and liver in vivo. 141 84


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