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)

A reversed phase gradient high performance liquid chromatographic method utilizing solid phase extraction has been described for the simultaneous determination of antipyrine (AP), 4-hydroxyantipyrine (4-OHAP), norantipyrine (NorAP) and 3-hydroxymethylantipyrine (3-OHMAP) in human urine after hydrolysis with beta-glucuronidase. The C-18 sorbent cartridges were conditioned and urine samples were applied, washed with 1 x 4 mL of phosphate buffer and eluted with 3 x 100 microL of 20% v/v of acetonitrile in methylene chloride. The eluent was evaporated to dryness, reconstituted in 100 microL phosphate buffer and injected. The calibration ranges were 2.0-250 micrograms/mL (AP), 2.5-250 micrograms/mL (NorAP), 2.0-250 micrograms/mL (3-OHMAP) and 5.0-500 micrograms/mL (4-OHAP) with regression coefficients of 0.998 or greater. Specificity was indicated by the absence of interferences in chromatogram of blank urine from normal as well as cirrhotic patients. The average recovery was 86.7% for AP, 90.5% for NorAP, 85.2% for 4-OHAP and 74.2% for 3-OHMAP. The within-assay precision as indicated by the reproducibility of the assayed spiked urine was less than 9% in all cases and the between-assay precision was less than 12%. The method was applied to studies on antipyrine metabolism in stable cirrhotic patients. Following administration of a single oral dose of about 1000 mg to nine stable cirrhotic patients and eight age-matched healthy volunteers, the cumulative account excreted in the urine up to 48 h for AP and the three metabolites was comparable to other literature reports.
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PMID:Solid phase extraction and simultaneous high performance liquid chromatographic determination of antipyrine and its major metabolites in urine. 128 89

This paper reports a HPLC method to detect unchanged and glucuronide derivatives of ciclopirox olamine (a substituted 2-pyridone antimycotic) and gives pharmacokinetics in rabbits after i.v. and intravaginal administration. The HPLC method utilizes a RP 18 reverse phase column, a mobile phase of water and acetonitrile (60/40), a flux of 1 ml/min and wavelength of 304 nm. For the determination of free ciclopirox the plasma drug is methylated with dimethyl sulphate, extracted with n-exane, purified on Adsorbex CN and injected into the column. For the determination of total (free and glucuronide derivatives) ciclopirox the plasma is previously hydrolized with beta-glucuronidase before the application of the above procedure. In rabbits the drug is administered at 15 mg/kg for both routes; the t1/2 elim is 2.1 hours, the total clearance/F is 0.73 1.h-1 and the distribution volume/F is 2.2 1. Ciclopirox olamine, after intravaginal administration, shows low absorption (about 2%) and is mainly transformed into glucuronide derivatives.
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PMID:HPLC method for pharmacokinetic studies on ciclopirox olamine in rabbits after intravenous and intravaginal administrations. 152 26

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

Previous research has demonstrated transmission of zearalenone and alpha- and beta-zearalenols into the milk of cows and other animals. Since human intake of zearalenone and its metabolites via milk is an unknown factor in risk assessment of zearalenone and because appropriate methodology for their determination in milk is not available, a rapid and sensitive analytical method has been developed. Essentially, the method includes extraction with basic acetonitrile, acidification, partition into methylene chloride on a hydrophilic matrix, cleanup on an aminopropyl solid phase extraction column, and reverse-phase liquid chromatography with fluorescence detection. Recoveries from milk averaged 84% for zearalenone, 93% for alpha-zearalenol, and 90% for beta-zearalenol at spiking levels of 0.5 to 20 ng/mL. As little as 0.2 ng/mL of zearalenone and alpha-zearalenol and 2 ng/mL of beta-zearalenol can be detected in milk. These 3 compounds are stable in refrigerated milk for at least 2 weeks and in milk brought to boiling. Enzymes (beta-glucuronidase and aryl sulfatase) may be added to milk prior to extraction to hydrolyze any conjugates.
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PMID:Liquid chromatographic determination of zearalenone and alpha- and beta-zearalenols in milk. 297 28

Procedures based on high-performance liquid chromatography (HPLC) were developed for identifying and measuring p-aminobenzoic acid (PABA) and its conjugate metabolites in human urine after oral doses of PABA. p-Aminohippuric acid (PAH), PABA, p-acetamidohippuric acid (PAHA) and p-acetamidobenzoic acid (PADB) in urine were resolved and determined by HPLC simultaneously and directly without extraction. A mobile phase consisting of 3% (v/v) acetonitrile in distilled water containing 0.005 M 1-heptanesulphonic acid in glacial acetic acid (PIC-B7) at pH 3.3 was eluted at 1 ml/min through a C18 Spherisorb column, followed by UV detection at 280 nm. After hydrolysis of urine samples at 37 degrees C for 3 h with beta-glucuronidase, the amounts of PABA-glucuronide and PADB-glucuronide were also determined. The retention times of PAH, a dominant peak which disappeared after hydrolysis, PABA, DABA (3,5-diaminobenzoic acid, as the internal standard), PAHA and PADB were 11.8, 14, 15, 18, 24 and 46 min, respectively. The 24-h urinary recoveries of PAH, PAHA, PADB, PADB-glucuronide, PABA and PABA-glucuronide after separate oral doses of 200 and 800 mg of PABA in one healthy subject were 43.4 and 48.1, 7 and 29.1, 11.2 and 11.8, 34.8 and 6.6, 0.2 and 0.3, and 1.0 and 2.4%, respectively. It is interesting that at high dose (800 mg) saturation of glucuronidation of PADB (N-acetylated PABA) appeared to occur, which resulted in an increase in the formation of PAHA, the glycine conjugate of PADB. Over 90% of the oral dose was accounted for by 8 h after administration.
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PMID:Direct and simultaneous high-performance liquid chromatographic assay for the determination of p-aminobenzoic acid and its conjugates in human urine. 326 Feb 39

A comprehensive high-performance liquid chromatographic method was developed for quantitating propranolol and its known metabolites in serum, bile and urine. Analysis was performed before and after incubation of the samples with beta-glucuronidase-arylsulfatase to quantitate both free and conjugate forms of the oxidative metabolites. Fractionation of the basic, neutral and acidic metabolites was achieved by differential pH solvent extraction. The basic and neutral metabolites were extracted from the biological samples at pH 10.5 with 2% n-butanol in dichloromethane. Additional clean-up of the basic fraction by back-extraction into dilute acid was needed for those samples that were subjected to enzymatic hydrolysis. The original aqueous sample was titrated with acid to pH 1, followed by extraction of the remaining acidic metabolites into either n-butanol-dichloromethane (with unhydrolyzed serum) or carbon tetrachloride (with all other samples). Chromatographic separation of the metabolites in the different extracts was achieved on a reversed-phase C18 column, using a single isocratic mobile phase consisting of 0.044 M pH 2.7 phosphate buffer, tetrahydrofuran, methanol and acetonitrile, with the addition of n-butylamine as a competing base to control retention volume and peak shape. Detection and quantitation of propranolol and its metabolites in the low nanogram to sub-nanogram range was afforded by fluorescence at a low UV excitation wavelength. The coefficients of variation for replicate assay of spiked samples were uniformly less than 6% for all the analytes.
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PMID:Versatile isocratic high-performance liquid chromatographic assay for propranolol and its basic, neutral and acidic metabolites in biological fluids. 357 4

Indirect measurement of salicylphenolic glucuronide (SPG) has suggested that the formation of this metabolite from therapeutic doses of salicyclic acid (SA) is capacity-limited in humans. A direct high performance liquid chromatographic (HPLC) assay for SPG in human urine is described. SPG was prepared by a published method and purified by HPLC. On treatment with beta-glucuronidase, SPG yielded the expected amount of SA. Spectroscopic data, melting point, and optical rotation of the glucuronide and/or its triacetyl dimethyl ester derivative were consistent with the proposed structure. SPG was assayed using a 5-micron C18 column (temperature 55 degrees C) and fluorescence detection. A nonlinear gradient mobile phase at a flow rate of 2 ml/min was used, beginning with 100% 0.1 M pH 2.1 phosphate buffer and finishing with 84% buffer, 16% acetonitrile. Total run time was 25 min. Urine (10 microliter) was injected directly on the column, and quantitation was performed using urine standards. Within-run precision for SPG ranged from 1.2% at 150 mg/L to 2.4% at 5 mg/L. The limit of detection was less than 1 mg/L. A pilot study in two volunteers, each receiving a single 500-mg dose of sodium salicylate, was carried out to validate the usefulness of the assay.
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PMID:Direct measurement of salicylphenolic glucuronide in human urine. 375 Mar 76

Chromatography of benzo[a]pyrene (BaP) sulfate, glucuronide and glutathione (GSH) conjugate standards were examined by h.p.l.c. on a C8 column as modified by various organic acids and solvents. Sulfate and glucuronide standards were positional isomers derived from BaP-1,3,6,7,9 phenols and BaP-GSH conjugates consisted of a racemic mixture of BaP-4,5-GSH. In the absence of acid, BaP conjugates appeared as rapidly eluting, unresolved peaks in aqueous-methanol or acetonitrile gradients or coeluted as broad peaks in a water-propanol gradient, with the exception of BaP-7-OH sulfate which eluted as a distinct symmetrical peak. Addition of acetic or trifluoroacetic (TFA) acids enhanced column retention of BaP conjugates in each solvent system. Upon acidification of mobile phases, BaP-GSH isomers were partially resolved, isomers of BaP sulfates or of BaP glucuronides coeluted, and BaP-7-OH sulfate was resolved from all conjugates. BaP-GSH conjugates were most resolved and preceded elution of other conjugates when TFA was added to mobile phases. BaP sulfates and glucuronides generally coeluted but were partially resolved at 0.1% TFA in a water-methanol gradient. Water-soluble metabolites from cultured hamster embryo fibroblasts (HEF) incubated with [3H]BaP for 24 h were chromatographed by h.p.l.c. in a water-methanol gradient with TFA. BaP glucuronides, consisting of tetraols, triols, quinones, dihydrodiols and phenols eluted as a single peak which could be removed by beta-glucuronidase treatment and organic extraction. BaP sulfates were not detected. The remaining BaP metabolites which were resistant to enzymatic hydrolysis, generally eluted prior to BaP glucuronides suggesting they constitute a family of BaP-GSH derivatives.
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PMID:H.p.l.c. of benzo[a]pyrene glucuronide, sulfate and glutathione conjugates and water-soluble metabolites from hamster embryo fibroblasts. 402 29

A reversed-phase high-performance liquid chromatographic (HPLC) method for the determination of four separate 1,4-benzodiazepine glucuronides in urine, plasma and bile is presented. We succeeded not only in determining the single glucuronides but also in separating the enantiomers (optical isomers) of the 1,4-benzodiazepine glucuronides. The optical isomers of the glucuronides of oxazepam and cinolazepam and of two other glucuronides of benzodiazepine metabolites could be well separated. The ratio of the isomers could be evaluated. An octadecyl reversed phase was used with a mobile phase of acetonitrile and 0.01 M orthophosphoric acid. After the initial separation, the isomers were fractionated by HPLC. After treatment with beta-glucuronidase to yield the aglycone, the separated fractions were hydrolysed to the corresponding benzophenones whose identity was confirmed by HPLC. Gas chromatography and gas chromatography-mass spectrometry demonstrated that the separated glucuronides corresponded to the enantiomeric benzodiazepines. Human urine and plasma as well as rabbit urine, plasma and bile were examined.
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PMID:Separation, isolation and identification of optical isomers of 1,4-benzodiazepine glucuronides from biological fluids by reversed-phase high-performance liquid chromatography. 671 62

An automated HPLC method is described for the simultaneous determination of propranolol, 4-hydroxypropranolol, and N-desisopropylpropranolol in plasma and urine before and after beta-glucuronidase/aryl sulfatase treatment. It involves extraction with ether at pH 10 in the presence of ascorbic acid, added to prevent oxidation of 4-hydroxypropranolol. The compounds are then back extracted into dilute acid and assayed on an HPLC using a fluorescence detector. Three HPLC columns have been used (a phenyl, an octyl, and an octadecyl column). The last column was found to be most reproducible with minimal intercolumn variation. The solvent system includes a combination of acetonitrile, methanol, and phosphoric acid. Concentrations as low as 0.2, 1.0, and 0.2 ng/ml of propranolol, 4-hydroxypropranolol, and N-desisopropylpropranolol, respectively, can be measured using 1 ml of plasma.
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PMID:An automated HPLC method for the assay of propranolol and its basic metabolites in plasma and urine. 707 80


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