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 routine gas chromatographic assay for urinary 5-(4-hydroxyphenyl)-5-phenylhydantoin (p-HPPH), the major metabolite of phenytoin (PHT) in man, was adapted to allow quantitation of 5-(3,4-dihydroxy-1,5-cyclohexadien-1-yl)-5-phenylhydantoin (Dihydrodiol, DHD) is based on the observation that acid-catalyzed dehydration of DHD quantitatively yields a mixture of p-HPPH and m-HPPH in a reproducible molar ratio of 56:44p-HPPH: m-HPPH and on the assumption that all m-HPPH found in urine after heating with acid has been derived from DHD. The urinary DHD content was verified by a "specific" method in which urine was incubated with beta-glucuronidase and the released phenolic metabolites completely removed by extraction. Subsequent acid-catalyzed dehydration of the remaining DHD yielded p-HPPH and m-HPPH, from the sum of which the original DHD concentration in urine could be calculated. In all of the urine samples from PHT patients examined to date, there was close agreement between the DHD values obtained by the "specific" method and those calculated from m-HPPH, in the simple acid-hydrolysis method. It can be inferred that much the greater part (greater than 90%) of m-HPPH found in human urine after acid treatment has been derived from DHD. All samples of urine after acid treatment has been derived from DHD. All samples of urine from PHT patients examined have shown detectable quantities of DHD. The methods described here may be useful in a survey of PHT patients to reveal unusual patterns of PHT metabolism and to permit recognition of possible associations between such unusual patterns and the occurrence of adverse reactions.
Ther Drug Monit 1979
PMID:Determination of 5-(3,4-Dihydroxy-1,5-cyclohexadien-1-yl)-5-phenylhydantoin (Dihydrodiol) and quantitative studies of phenytoin metabolism in man. 55 79

A rapid and simple high-performance liquid chromatography analytical method is described for the quantitative determination of phenytoin and five of its metabolites--phenytoin dihydrodiol, catechol, methoxycatechol, para-hydroxyphenytoin, and meta-hydroxyphenytoin--in biological materials. Following ethyl acetate extraction and incubation with beta-glucuronidase, samples were passed through a C18 Sep-Pak cartridge. The eluate was chromatographed on a reverse-phase 10 cm C18 Radial Nova-Pak (5 micron) column using a mobile phase of isopropanol:water (20:80) at a flow rate of 1.4 ml/min and monitored at 235 nm. Total chromatographic analysis time was 23 min, with complete baseline resolution of all metabolites. Five different columns and 10 different mobile phase conditions were studied to determine the best system. The 10-cm C18 Radial Nova-Pak (5 micron) gave the best resolution, reproducibility, and durability. This method should prove applicable for clinical use as well as for research purposes.
Ther Drug Monit 1989
PMID:Isocratic separation of phenytoin metabolites by high-performance liquid chromatography from human and animal microsomes and urine. 291 55

Identifying individuals with a deficient capacity for oxidative drug metabolism is of increasing clinical importance. Dextromethorphan (DM) is gaining wide acceptance as a probe drug to characterize individual expression of a specific cytochrome P-450 isozyme. The thin-layer chromatography (TLC) technique described in the present study is a rapid and inexpensive alternative to the methods currently available for assessing the urinary metabolic profile of DM. Sixty-five healthy volunteers participated in the study by ingesting 213 mmol DM and collecting all urine for the ensuing 8 h. Urine samples were analyzed by TLC and high-performance liquid chromatography (HPLC) after treatment with beta-glucuronidase. Based on the relative color intensities of DM and its O-demethylated metabolite, dextrorphan, the TLC analysis provided an accurate phenotype assessment. A greater intensity of the parent drug relative to the metabolite indicates a poor metabolizer phenotype whereas a reversed relative intensity indicates the extensive metabolizer phenotype. The phenotype assignments made by TLC were verified by comparison with the quantitative results (based on metabolic ratios) obtained from HPLC analysis. Complete agreement was found between the two methods. The routine implementation of phenotype determination into clinical protocols can be realized with this facile TLC technique.
Ther Drug Monit 1988
PMID:Simplified phenotyping with dextromethorphan by thin-layer chromatography: application to clinical laboratory screening for deficiencies in oxidative drug metabolism. 320 36

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.
Ther Drug Monit 1986
PMID:Direct measurement of salicylphenolic glucuronide in human urine. 375 Mar 76

A method using gas-liquid chromatography-electron-capture detection method is described for rapid, accurate determination of SAS 643 in plasma and urine. The drug is extracted from biological fluid with benzene and converted to the O, O'-bistrimethylsilyl derivative with bis(trimethylsilyl) trifluoroacetamide. The glucuronide form of the drug is extracted after hydrolysis with beta-glucuronidase. Nimetazepam is used as internal standard. Moreover, some metabolites such as glucuronide and the N-1-dealkylated and N-1-yl-acetic products are identified. All compounds were confirmed by thin-layer chromatography, mass spectroscopy, and gas-liquid chromatography-mass spectroscopy by comparison with reference products.
Ther Drug Monit 1981
PMID:GLC-ECD determination of 1-(2-hydroxyethyl)-3-hydroxy-7-chloro-1,3-dihydro-5-(O-fluorophenyl)-2H-1,4-benzodiazepin-2-one (SAS 643) in plasma and urine and identification of its main biotransformation products. 612 4

Elevations of serum beta-glucuronidase (GRS) enzyme activity can occur under a variety of pathological conditions. Using phenolphthalein glucuronic acid as the substrate, 158 epileptic patients were randomly screened for GRS. GRS was distinctly elevated (65.9 +/- 30.0 micrograms phenolphthalein/ml serum) in patients, compared with the normal group (27.0 +/- 10.0). No difference in GRS levels were found when seizure-free (greater than 1 year) patients (n = 61; GRS, 62.6 +/- 32.7 micrograms) were compared with patients who had seizure episodes within 1 week (n = 26; GRS, 73.2 +/- 24.9 micrograms), and there were no differences when intermediate groups were examined. GRS elevations were found to be linearly and directly correlated with free phenytoin ultrafiltrate levels (n = 35, r = 0.7692, p less than 0.0001) when patients were co-medicated with valproic acid, with serum phenobarbital levels (n = 58, r = 0.5361, p less than 0.05), with serum valproic acid levels (n = 43, r = 0.3173, p less than 0.05), and with the sum of serum phenobarbital and valproic acid levels (n = 16, r = 0.8657, p less than 0.0001). The findings indicate that GRS elevations are probably due to anticonvulsant medications rather than to the frequency of seizures. There is no evidence that GRS determinations can be used for the diagnosis or prognosis of patients with epilepsy.
Ther Drug Monit 1984
PMID:Elevation of beta-glucuronidase activity in medicated patients with epilepsy. 671 May 57

In this assay of the nonsteroidal antiestrogen droloxifene and two metabolites in human serum, the serum samples were deproteinized with an equal volume of acetonitrile and then injected into an analytical octadecylsilane column. The analytical column was equilibrated with acetonitrile/water (1/1, vol/vol) containing acetic acid and diethyl amine and eluted isocratically with 66% acetonitrile in the same buffer. Droloxifene, N-desmethyldroloxifene, and 4-methoxdroloxifene were post-column converted to fluorophors by ultraviolet illumination while passing through a 10-m transparent knitted polytetrafluorethylene reaction coil. Analytical recovery was close to 100%. Within- and between-day precision corresponded to a coefficient of variation (CV) of 2-5% at serum concentrations of > or 25 ng/ml, except for 4-methoxydroloxifene (CV 7-10% at a concentration of 25 ng/ml). By increasing the injection volume from 50 to 250 microliters, the detection limits could be decreased from approximately 5 to 1 ng/ml. Conjugated droloxifene could be estimated in a second run after treatment of sample with an enzyme preparation containing beta-glucuronidase plus sulphatase. The recovery of droloxifene glucuronide was close to 100%. Sulphate conjugates have not been identified and were not accounted for.
Ther Drug Monit 1995 Jun
PMID:Determination of droloxifene and two metabolites in serum by high-pressure liquid chromatography. 762 22

This assay method allows a simultaneous determination of imipramine, desipramine, their 2-hydroxylated metabolites, and imipramine-N-oxide in 0.5 ml of plasma or 0.1 ml of urine within 35 min by an ion-paired, reversed phase (C18) high-performance liquid chromatography (HPLC) with electrochemical detection. The analytes are extracted from alkalinized plasma or urine with 5 ml of a 90/10 mixture (by vol) of diethyl either/2-propanol, back-extracted into 0.5 ml of 0.1 mol/L phosphoric acid. Urine samples are enzymatically treated with beta-glucuronidase/arylsulfatase before extraction. The electrochemical detection is performed with a glassy carbon electrode set at +0.85 V against the Ag/AgCl reference electrode. Recoveries for the analytes and the internal standard (propericiazine) from plasma or urine ranged from 66.4 to 105.7% with coefficients of variation (CVs) of < 6.8%. The intra- and interassay CVs for the analytes were < 17.4% in plasma and < 14.2% in urine. The limits of determination (a signal-to-noise ratio of 3) for imipramine, desipramine, 2-hydroxyimipramine, 2-hydroxydesipramine, and imipramine-N-oxide were 0.5, 0.3, 0.02, 0.02, and 1.0 microgram/L, respectively. Only four of the 23 psychotropic drugs, which might be coadministered with imipramine or desipramine, were considered to be the possible sources to interfere with the assay. We evaluated clinical applicability of this method by determining plasma concentration- and urinary excretion-time courses of the respective analytes in an extensive and a poor metabolizer of the debrisoquine/sparteine-type oxidation after a single oral dose of imipramine HCl (25 mg). The present method appears to be suitable not only for the therapeutic drug monitoring of imipramine and its active metabolites but also for studying the pharmacogenetically related metabolism of imipramine or desipramine.
Ther Drug Monit 1993 Jun
PMID:Simultaneous high-performance liquid chromatography-electrochemical detection determination of imipramine, desipramine, their 2-hydroxylated metabolites, and imipramine N-oxide in human plasma and urine: preliminary application to oxidation pharmacogenetics. 833 3

A method has been developed for the simultaneous determination of antipyrine and its three major metabolites in plasma of patients with renal failure. Plasma samples (500 microl) were hydrolyzed with beta-glucuronidase/aryl sulphatase. The compounds, after addition of sodium chloride, were extracted with chloroform:ethanol (90:10, v/v) in acidic medium. Chromatographic conditions comprise a C18 column, a mobile phase with 30% methanol and 70% 0.25N sodium acetate buffer (pH 5.0), a total run time of 10 minutes, and ultraviolet absorbance detection at 254 nm. Confidence limits showed 0.5 to 40.0 microg/ml(-1) linearity (r2 = 0.999); 0.1 microg/ml(-1) HMA, 0.05 microg/ml(-1) antipyrine and NORA, and 0.5 microg/ml(-1) OHA sensitivity and absolute recovery >95%. Interprecision and intraprecision expressed as coefficient of variation were <10% for all compounds investigated. The assay shows to be suitable for pharmacokinetics and drug metabolism studies after administration of a single oral dose of 500 mg of antipyrine to a patient with hypertension and chronic renal failure (CL(CR) = 34.17 ml/min(-1); 1.73 m(-2)).
Ther Drug Monit 1997 Dec
PMID:Determination of antipyrine and metabolites in plasma of a patient with mild renal failure. 942 Nov 15

Four healthy patient subjects were each given a single, 1-mg lorazepam tablet. Urine samples from all patient subjects were collected at 12 intervals (0-2, 2-5, 5-8, 8-11, 11-14, 14-24, 24-26, 26-29, 29-32, 32-35, 35-38, and 38-48 hours). An aliquot from each urine collection was screened using cloned enzyme donor immunoassay (CEDIA), enzyme-multiplied immunoassay technique (EMIT) II, EMIT dau, and fluorescence polarization immunoassay (FPIA) without and with hydrolysis using beta-glucuronidase. Using a 200 ng/mL calibrator cut-off, none of the four immunoassays gave a positive response before hydrolyzation of the urine samples. For offline hydrolysis using Helix pomatia beta-glucuronidase, 35, 3, 0, and 4 of 48 urine samples gave positive responses on the previously listed immunoassays. The CEDIA method also gave 32 of 48 positive responses for online hydrolysis using Escherichia coli beta-glucuronidase. Online hydrolysis can be conveniently automated by including the beta-glucuronidase in the first of the two reagents combined with the urine sample.
Ther Drug Monit 1998 Dec
PMID:Comparison of four immunoassays for the detection of lorazepam in urine. 985 86


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