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)

Since the biotransformation of paracetamol (Acetaminophen) is practically confined to conjugation, the quantitative determination of paracetamol excretion may provide important information on phase II of the drug metabolism. We elaborated a simple and rapid liquid chromatographic method for the assessment of paracetamol and its conjugated metabolites in the urine to be available for routine use in the clinicopharmacological laboratory. The persons involved in the trial were administrated 500 mg of paracetamol to be taken on an empty stomach in the morning. Subsequently, their urine was collected for 8 hours. The so-called free paracetamol of unchanged form excreted into the urine was measured from this 0 to 8 hours' urine fraction, then, after treating it with beta-glucuronidase/arysulphatase enzyme, the total amount of paracetamol released from the conjugate, as well as that of the existing free paracetamol, the so-called total paracetamol were determined. The urine extracts containing paracetamol obtained by ethylacetate, at pH 10, and dried under nitrogen stream were analysed by HPLC on an ODS column in an eluent of methanol and water mixture (3:7, v/v) in the presence of 3-acetaminophenol internal standard. The flow rate was 1 ml/min, the detection wavelength was 254 nm.
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PMID:[Determination of paracetamol in urine by liquid chromatography]. 223 43

A simple rapid method for simultaneous ethosuximide and phenobarbital assay in brain tissue, serum and urine has been developed. Extraction of samples from brain tissue and serum were performed with dichloromethane at low pH in the presence of an excess of ammonium sulfate. Glucuronide conjugates in urine samples were hydrolyzed by enzymatic cleavage with beta-glucuronidase and then extracted with dichloromethane. The extracts were analyzed using a Spherisorb 5 ODS column and a mixture of acetonitrile, methanol and phosphate buffer (21:24:55, v/v) as eluent. No interference was encountered and the method is both precise and reproducible.
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PMID:Simultaneous measurement of ethosuximide and phenobarbital in brain tissue, serum and urine by HPLC. 273 17

The glucuronide of N-1-hydroxy-ethyl flurazepam has been analysed by a direct liquid inlet liquid chromatographic/mass spectrometric system using MeOH/H2O (70:30 v/v) as mobile phase, at a flow rate of 0.7 ml min-1. Urine samples were purified by amberlite XAD-2 chromatography; the glucuronide was quantified by high-performance liquid chromatography using a counterion (tetrabutyl ammonium nitrate in methanol). Chromatographic results were validated by an enzymatic method: treatment of the samples with beta-glucuronidase and extraction of the parent drug with ethyl ether at pH 9. The biological application of this method was demonstrated by determination of this glucuronide in the urine of healthy human volunteers following a single intravenous administration of 50 mg of N-1-hydroxy-ethyl flurazepam.
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PMID:Direct liquid inlet liquid chromatographic/mass spectrometric identification and high-performance liquid chromatographic analysis of a benzodiazepine glucuronide. 276 96

A high-performance liquid chromatographic method for the determination of triazolam and its main metabolites (1-hydroxymethyltriazolam and 4-hydroxytriazolam) in human urine has been developed. After hydrolysis with beta-glucuronidase, the unchanged drug and its metabolites were extracted with a Sep-Pak C18 cartridge and further purified by a Sep-Pak silica cartridge. The extract was chromatographed on a reversed-phase column using a mobile phase consisting of methanol-10 mM phosphate buffer, pH 8 (65:35) and UV detection at 220 nm. The overall recoveries of triazolam, 1-hydroxymethyltriazolam and 4-hydroxytriazolam were ca. 88, 75 and 75%, respectively, and the detection limits of these compounds were 5 ng/ml, using a 10-ml specimen.
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PMID:High-performance liquid chromatographic determination of triazolam and its metabolites in human urine. 283 Feb 92

A post-column enzyme reactor, containing beta-glucuronidase immobilized on controlled-pore glass beads, was developed for use in the high-performance liquid chromatographic (HPLC) analysis of glucuronide metabolites using electrochemical detection. The reactor performance was evaluated with glucuronide conjugates of the new antihypertensive agent, fenoldopam [6-chloro-2,3,4,5-tetrahydro-1-(4-hydroxyphenyl)-1H-3-benzazepine-7,8-di ol]. These conjugates, which are electrochemically inactive at 0.6 V vs. Ag/AgCl, were separated by HPLC and passed directly into the post-column beta-glucuronidase reactor, which converted the glucuronides to their electrochemically active aglycone, fenoldopam. The enzyme reactor converted greater than 80% of the entering glucuronide to fenoldopam and produced a linear response for fenoldopam glucuronide in the range 0.4-200 ng injected on-column. The reactor performance was optimal when the mobile phase (methanol-acetate buffer) contained 0-25% methanol, but the efficiency gradually declined thereafter until, at 50% methanol, the reactor was inactive. The working pH range for the mobile phase was 5.5-8.0, with a performance optimum at pH 6.0. The reactor displayed marked stability during usage (greater than 4 months) and during storage (greater than 6 months). The reactor did not hydrolyze the 8-O-sulfate conjugate of fenoldopam but did convert the 1(R) and 1(S) diastereomers of fenoldopam-7-O-beta-glucuronide and 1(S)-fenoldopam-8-O-beta-glucuronide to fenoldopam. An assay was developed for 1(R)-fenoldopam-7-O-beta-glucuronide in plasma and urine by using the deschloro, des-4'-hydroxy analogue of fenoldopam glucuronide as the internal standard. The assay was linear in the range 4-1600 ng/ml. The within-day and between-day coefficients of variation for the method were less than 7% at three plasma fenoldopam glucuronide concentrations.
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PMID:Use of a post-column immobilized beta-glucuronidase enzyme reactor for the determination of diastereomeric glucuronides of fenoldopam in plasma and urine by high-performance liquid chromatography with electrochemical detection. 287 Oct 34

When small doses of [3H]D3, [3H]25-OHD3 and [3H]alpha, 25-diOHD3 were administered intravenously to rats 6.3 +/- 1.1% (means +/- SEM, n = 4), 9.7 +/- 0.9% (n = 6) and 12.8 +/- 2.6% (n = 8), respectively, of the administered radioactivity was excreted in bile. The radioactive biliary conjugated metabolites were analysed by ion exchange chromatography: in the case of all 3 substrates about 30% of metabolites were found to be cationic on the basis of their being retained on sulphopropyl-Sephadex G-25 (H+-form) when applied in 70% methanol. The balance of the metabolites were neutral and anionic and were analysed on TEAP-Lipidex: in the case of 1 alpha, 25-diOHD3 the following metabolite classes were detected (on the basis of co-elution with authentic standards) (in order of quantitative importance): taurine conjugates, neutral metabolites, monosulphates, glucuronides, carboxylic acids, glycine conjugates and disulphates. Alkaline hydrolysis of the taurine and glycine conjugates yielded products 60% of which now chromatographed as carboxylic acids. Hydrolysis of the glucuronide and monosulphate fractions indicated significant levels of mixed conjugation yielding some products which now chromatographed as glycine and taurine conjugates, respectively. The nature of the cationic conjugates was not elucidated but they had the following properties: they could be hydrolysed by alkali to yield non-cationic radioactive metabolites (these released metabolites were heterogeneous as judged by TEAP-lipidex chromatography); they were partially hydrolysed to non-cationic forms by beta-glucuronidase; and on reverse-phase HPLC they had an elution profile that was significantly different to that of histidyl-, ornithyl- or lysyl-calcitroic acid.
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PMID:Conjugated forms of [3H] alpha, 25-dihydroxyvitamin D3 in rat bile. 303 52

The administration of [3H]BPDE-DNA, whether by i.p. or i.v. injection, to male Wistar rats resulted in the majority of the radioactivity being recovered in the faeces. Excretion was rapid: within 24 h post-injection, 45% of the applied dose was recovered in the faeces. H.p.l.c. analysis of radioactive material extracted from the faeces by methanol showed that it contained a single component which co-chromatographed with [3H]BPDE-dGuo and which was not affected by treatment with alkaline phosphatase, aryl sulphatase or beta-glucuronidase. To determine if this phenomenon occurs after topical application of BP to a target tissue, such as mouse skin, animals were treated with [3H]BP and their faeces collected. After an extensive extraction procedure involving differential solubility in organic solvents, Sephadex LH-20 chromatography and h.p.l.c., a product was isolated from mice faeces which had characteristics consistent with a [3H]BPDE-dGuo adduct. These findings are discussed in relation to detection of BPDE adducts in human populations.
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PMID:Topical treatment of mice with benzo[a]pyrene or parenteral administration of benzo[a]pyrene diol epoxide-DNA to rats results in faecal excretion of a putative benzo[a]pyrene diol epoxide-deoxyguanosine adduct. 311 51

The urine of mice injected intraperitoneally with pyrene during exposure to NO2 was found to contain highly mutagenic compounds by means of the Ames test using Salmonella typhimurium strain TA98. The mice were exposed to 20 ppm NO2 for 3 days before intraperitoneal injection of pyrene (800 mg/kg of body weight). The pyrene-treated mice were further exposed to NO2 for an additional 24 hr, and the urine from the mice was collected in ice-cooled containers and stored frozen in the dark. The collected samples were treated with beta-glucuronidase and passed through activated Sep-Pack C18 cartridges. After elution with methanol, the effluent was concentrated and the residue was dissolved in dimethyl sulfoxide (DMSO). The DMSO solution was fractionated by high-performance liquid chromatography and the mutagenicity of each fraction was assayed with S. typhimurium strain TA98. The mutagenic compounds 3-hydroxy-1-nitropyrene, 6-hydroxy-1-nitropyrene, 8-hydroxy-1-nitropyrene, and 1-hydroxypyrene were identified in the mutagenic fractions by mass spectrometry and UV-visible spectrophotometry with synthetic reference substances. These mutagenic compounds may have been formed by either nitration of hydroxylated pyrene, or hydroxylation of 1-nitropyrene, which is formed in vivo from pyrene and NO2, or the simultaneous occurrence of these two reactions in the mouse body.
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PMID:Detection of mutagenic compounds in the urine of mice administered pyrene during exposure to NO2. 311 37

A liquid chromatographic (LC) method is described for the determination of the plant estrogens diadzein, formononetin, and coumestrol and the estrogenically active metabolite equol in bovine blood plasma and urine. The blood and urine samples are incubated overnight with and without beta-glucuronidase/sulfatase for analysis of both free and conjugated forms of estrogens. Samples are applied to Extrelut columns, extracted with ethyl acetate, and evaporated to dryness. Residues from urine samples are dissolved in methanol, diluted with water, acidified with HCl, and purified by injection through a Sep-Pak C18 cartridge. This eluate is used for LC analysis. Residues from blood samples are dissolved in benzene-petroleum ether (1 + 1), extracted with ammonium hydroxide, acidified with glacial acetic acid, and extracted with ethyl acetate. The ethyl acetate extract is evaporated, dissolved in 80% methanol, injected onto a LC reverse-phase column, and separated in a linear gradient system between 40 and 80% methanol in phosphate buffer. Quantitation is performed by means of UV and fluorescence responses. The method was sensitive enough to determine 0.4 ng/mL of daidzein and formononetin and 0.1 and 13 ng/mL of coumestrol and equol, respectively, in blood, and 130, 80, and 7 ng/mL of daidzein, formononetin, and coumestrol, respectively, and 4 micrograms/mL of equol in urine. The applicability of the method was checked by the determination of total and free plant estrogens in blood samples from a dairy cow fed a normal diet.
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PMID:Liquid chromatographic determination of the estrogens daidzein, formononetin, coumestrol, and equol in bovine blood plasma and urine. 323 13

15 hazardous industrial waste samples were evaluated for mutagenicity in the Salmonella plate-incorporation assay using strains TA98 and TA100 in the presence and absence of Aroclor 1254-induced rat liver S9. Dichloromethane/methanol extracts of the crude wastes were also evaluated. 7 of the crude wastes were mutagenic, but only 2 of the extracts of these 7 wastes were mutagenic; extracts of 2 additional wastes also were mutagenic. In addition, 10 of the crude wastes were administered by gavage to F-344 rats, and 24-h urine samples were collected. Of the 10 raw urines evaluated, 3 were mutagenic in strain TA98 in the presence of S9 and beta-glucuronidase. The 3 crude wastes that produced these 3 mutagenic urines were, themselves, mutagenic. Adequate volumes of 6 of the 10 raw urines were available for extraction/concentration. These 6 urines were incubated with beta-glucuronidase and eluted through Sep-Pak C18 columns; the methanol eluates of 3 of the urines were mutagenic, and these were the same 3 whose raw urines also were mutagenic. In general, the C18/methanol extraction procedure reduced the cytotoxicity and increased the mutagenic potency of the urines. To our knowledge, this is the first report of the mutagenicity of urine from rodents exposed to hazardous wastes. Based on the present results, the use of only strain TA98 in the presence of S9 might be adequate for general screening of hazardous wastes or waste extracts for genotoxicity. The urinary mutagenesis assay does not appear to be a useful adjunct to the Salmonella assay for screening hazardous wastes. The problems associated with chemically fractionating diverse types of hazardous wastes for bioassay are also discussed.
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PMID:Mutagenicity in salmonella of hazardous wastes and urine from rats fed these wastes. 331 35


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