Search results for "Glucuronide"
showing 10 items of 40 documents
Metabolism of propafenone and verapamil by cryopreserved human, rat, mouse and dog hepatocytes: comparison with metabolism in vivo
2003
In the present study we examined the metabolism of [(14)C]propafenone (P) and [(14)C]verapamil (V) using cryopreserved human, dog (Beagle), rat (Sprague-Dawley) and mouse (NMRI) hepatocytes. The percentage ratios of the metabolites were identified after extraction by HPLC with UV and radioactivity detection. Phase-II metabolites were cleaved using beta-glucuronidase. Metabolism of the drugs by cryopreserved hepatocytes was compared with that in the respective species in vivo. All phase-I and -II metabolites known from in vivo experiments: 5-hydroxy-P (5-OH-P); 4'-hydroxy-P (4'-OH-P); N-despropyl-P (NdesP) and the respective glucuronides, were identified after incubation with cryopreserved h…
Species differences, influence of dose and application on biotransformation of phenol in fish.
1983
1. The metabolism of phenol in goldfish (Carassius auratus), rainbow trout (Salmo gairdneri) and goldenorfe ide (Leuciscus ideus melanotus) was compared. All three species produced phenyl sulphate, quinol sulphate and phenyl glucuronide. 2. The dose dependence of metabolism of phenol in goldfish was investigated. When the concn. of phenol was increased from 0.2 to 2 mg/l medium, that glucuronylated increased from 7 to 16% and that sulphated decreased from 63 to 47%. 3. The influence of mode of exposure on metabolism of phenol in goldfish was examined. Dietary exposure and uptake from medium was compared with i.p. injection. There was less metabolism in the order: dietary exposure greater th…
Effect of leaf removal and ripening stage on the content of quercetin glycosides in Sangiovese grapes
2021
Quercetin haze has been observed over the last few years in some aged Sangiovese wines. This problem could be due to an excess of the quercetin in the wine. Leaf removal increases the exposition of clusters to sunlight, which may enhance flavonol synthesis in the grapes. In this study, we evaluated the dynamics related to extractable flavonols in grapes grown in three usually defoliated Vitis vinifera (L.) cv. Sangiovese vineyards, whose wines showed quercetin precipitates. The particular structure of the vineyards in which the leaf removal experiments were carried out allowed the influence of vineyard, biotype and rootstock on grape flavonol contents at mid-maturation and technological mat…
Stability of 11-Nor-Δ9-carboxy-tetrahydrocannabinol Glucuronide in Plasma and Urine Assessed by Liquid Chromatography-Tandem Mass Spectrometry
2002
Abstract Background: Unconjugated 11-nor-Δ9-carboxy-tetrahydrocannabinol (THCCOOH) in blood and urine has been proposed as a valuable marker, but the glucuronide (THCCOOglu) is present in considerably higher concentrations than the parent drug. Acyl glucuronides have been shown to be potentially reactive conjugates, which may affect the in vitro metabolite pattern. Methods: Extraction procedures and a liquid chromatography-tandem mass spectrometry assay were developed and validated to investigate the stability of THCCOOglu in urine and plasma. Plasma and urine samples with added THCCOOglu were stored at −20, 4, 20, and 40 °C up to 10 days. Results: The glucuronide was stable at −20 °C in bo…
In vitro glucuronidation of 7-hydroxycoumarin derivatives in intestine and liver microsomes of Beagle dogs
2019
Beagle dog is a standard animal model for evaluating nonclinical pharmacokinetics of new drug candidates. Glucuronidation in intestine and liver is an important first-pass drug metabolic pathway, especially for phenolic compounds. This study evaluated the glucuronidation characteristics of several 7-hydroxycoumarin derivatives in beagle dog's intestine and liver in vitro. To this end, glucuronidation rates of 7-hydroxycoumarin (compound 1), 7-hydroxy-4-trifluoromethylcoumarin (2), 6-methoxy-7-hydroxycoumarin (3), 7-hydroxy-3-(4-tolyl)coumarin (4), 3-(4-fluorophenyl)coumarin (5), 7-hydroxy-3-(4-hydroxyphenyl)coumarin (6), 7-hydroxy-3-(4-methoxyphenyl)coumarin (7), and 7-hydroxy-3-(1H-1,2,4-t…
Endocrinology: Substrate dependency of C19 conjugates in hirsute hyperandrogenic women and the influence of adrenal androgen
1995
Serum C19 conjugates, specifically 3 alpha-androstanediol glucuronide (3 alpha G), reflect peripheral androgen action through the action of 5 alpha-reductase activity. The origin of 5 alpha-reduced C19 conjugates has been controversial and it has been suggested that they are derived primarily from adrenal androgens. We examined concentrations of 3 alpha G, 3 alpha-androstanediol sulphate (3 alpha S), androsterone glucuronide (AoG) and androsterone sulphate (AoS) in 40 hirsute hyperandrogenic women. These patients were divided into four groups based upon individual, combined or normal concentrations of the adrenal androgens dehydroepiandrosterone (DHEAS) and 11 beta-hydroxy-androstenedione. …
The association of serum androsterone glucuronide with inflammatory lesions in women with adult acne1
2002
Serum androsterone glucuronide (AoG) is a metabolite of circulating androgens under the influence of 5α-reductase activity and has been shown to be particularly elevated in women with acne. In this study, we wanted to evaluate changes in AoG before and after treatment with an oral contraceptive or placebo, and to assess whether changes correlated with the number and type of acne lesions. In order to accomplish these aims, we obtained sera from a completed prospective randomized trial, which was designed to assess the effectiveness of an oral contraceptive compared to placebo. Assessments were carried out in 56 women with moderate acne who were treated with Ortho Tri-Cyclen (norgestimate and…
Serum androsterone conjugates differentiate between acne and hirsutism in hyperandrogenic women
1991
Objective To determine if among hyperandrogenic women acne may be differentiated from hirsutism by markers of peripheral androgen metabolism. Design Prospective outpatient study of 36 hyperandrogenic women and controls divided into groups based on the presence or absence of significant hirsutism and the presence or absence of moderate to severe acne. Serum levels of adrenal and ovarian derived androgens were elevated but similar in all patient groups. Interventions Measurement of serum androgens including metabolites of 5 α -reductase activity: 3 α -androstanediol glucuronide and sulfate and androsterone (A) glucuronide and sulfate. Results 3 α -androstanediol glucuronide and sulfate were e…
Carboxyl nonsteroidal anti-inflammatory drugs are efficiently glucuronidated by microsomes of the human gastrointestinal tract.
2004
Limited studies have been carried out on the biotransformation of carboxyl nonsteroidal anti-inflammatory drugs (NSAIDs) in the liver. However, the role of the intestine in NSAID metabolism has not been investigated. In this report, the contribution of UDP-glucuronosyltransferases (UGTs) in the human gastrointestinal (GI) tract from five donors to the glucuronidation of the NSAIDs, RS-ketoprofen, S-naproxen, RS- and S-etodolac, was investigated. UGT activity and, for some donors, mRNA levels were evaluated. All NSAIDs were glucuronidated throughout the GI tract; however, glucuronidation was low in stomach and duodenum as compared to the remainder of the intestine. RT-PCR analysis demonstrat…
EtG Quantification in Hair and Different Reference Cut-Offs in Relation to Various Pathologies: A Scoping Review
2022
Ethyl glucuronide (EtG) is a non-volatile, non-oxidative, hydrophilic, and stable ethanol phase II metabolite. EtG is produced through ethanol glucuronidation by UDP-glucuronosyltransferase (UGT), a phase II enzyme. EtG can be extracted from different biological matrices, including keratin ones, such as hair or nails. The purpose of this scoping review is to describe the relationship between EtG levels in hair and some of the most common and frequent pathological conditions and verify whether different reference cut-offs in relation to various pathologies have been identified in the scientific literature. In fact, in-depth knowledge of the influence of pathologies, such as diabetes mellitus…