• We propose that glucuronide conjugates of quercetin function not only as detoxified metabolites but hydrophilic bioactive agents to various ROS-generating systems and precursors of hydrophobic aglycone. (rsc.org)
  • Nevertheless, quercetin is completely converted into its conjugated metabolites by phase-II enzymes during intestinal absorption. (rsc.org)
  • 13 Conjugated quercetin metabolites accumulate in human atherosclerotic lesion sites, but not in normal arteries. (rsc.org)
  • These metabolites underwent extensive phase II metabolism to yield sulfate and glucuronic acid conjugates. (cdc.gov)
  • Levonorgestrel and its phase I metabolites are excreted primarily as glucuronide conjugates. (empr.com)
  • Major metabolites of salicylic acid are its acyl and phenolic glucuronide conjugates. (aspetjournals.org)
  • These CYP-based metabolites are expected to be further metabolized to more water soluble conjugates (such as glucuronides by glucuronidation). (europa.eu)
  • The metabolites have not been fully characterized in spite of extensive LC-MS and GC-MS analyses but preliminary data indicate that they are glucuronide or sulfate conjugates. (europa.eu)
  • Elimination of water-soluble conjugated metabolites of the study substance occurs in the kidney with their ultimate excretion in the urine. (europa.eu)
  • Results from the oral radioactivity ADME studies indicate that urinary metabolites are comprised of glucuronide or sulfate conjugates (i.e., water-soluble, non-toxic). (europa.eu)
  • These other metabolites are not known to have any pharmacologic effects, and are further converted in part by conjugation (phase II metabolism) into polar metabolites, mainly sulfates and glucuronides. (druglib.com)
  • Sulfate and glucuronide conjugates of both ethinyl estradiol and phase I metabolites, which are excreted in bile, can undergo enterohepatic circulation. (druglib.com)
  • The hydroxylated metabolites were excreted in the urine as the O-glucuronide and/or O-sulfate conjugates, but traces of free 4-hydroxy-3-methoxymethamphetamine and 4-hydroxy-3-methoxyamphetamine were also present in unhydrolyzed urine. (erowid.org)
  • Human exposure to consumer and personal care products chemicals such as phenols, including parabens and other antimicrobial agents, can be assessed through biomonitoring by quantifying urinary concentrations of the parent chemical or its metabolites, often after hydrolysis of phase II conjugates. (cdc.gov)
  • It is known that glucuronide and/or sulfate conjugates with or without O -methylation exclusively circulate in the human bloodstream after intake of a quercetin-containing diet. (rsc.org)
  • Phase II enzymes present in the intestinal epithelial cells and the liver cells facilitate their metabolic conversion to glucuronide and sulfate conjugates. (rsc.org)
  • Estradiol glucuronide can be converted back into estradiol, and a large circulating pool of estrogen glucuronide and sulfate conjugates serves as a long-lasting reservoir of estradiol that effectively extends its elimination half-life of oral estradiol. (wikipedia.org)
  • UGTs catalyze the conjugation of xenobiotics to UDP-glucuronic acid, allowing the conjugated product to be excreted in the urine and feces. (aspetjournals.org)
  • Addition of glucuronic acid was catalyzed by specific UGTs at positions 2, 3, and 4 of the estrogens, whereas only E(2) was conjugated at position 17 by UGT2B7. (nih.gov)
  • UDP-glucuronosyltransferases (UGTs) are phase II metabolic enzymes that conjugate estrogens with glucuronic acid to render them more watersoluble. (helsinki.fi)
  • UGTs conjugate lipophilic compounds with glucuronic acid from UDP-glucuronic acid (UDPGA), thereby increasing hydrophilicity and enhancing excretion through bile and urine ( Dutton, 1980 ). (aspetjournals.org)
  • In demonstration of the importance of first-pass metabolism and the estrogen conjugate reservoir in the pharmacokinetics of estradiol, the elimination half-life of oral estradiol is 13 to 20 hours whereas with intravenous injection its elimination half-life is only about 1 to 2 hours. (wikipedia.org)
  • Estetrol undergoes conjugative metabolism to form glucuronide and sulphate conjugates. (uspharmacist.com)
  • We discovered that a conjugated metabolite derived from quercetin possesses considerable anti-oxidant activity in several in vitro experiments. (rsc.org)
  • Estradiol glucuronide, or estradiol 17β-D-glucuronide, is a conjugated metabolite of estradiol. (wikipedia.org)
  • The positional isomer of estradiol glucuronide, estradiol 3-glucuronide, also occurs as a major endogenous metabolite of estradiol, circulating at two-thirds of the levels of estrone sulfate when it reaches its maximal concentrations just before ovulation and during the peak in estradiol levels that occurs at this time. (wikipedia.org)
  • To address this, concentrations of testosterone, sex hormone binding globulin, androstanediol glucuronide (a metabolite of dihydrotestosterone) and estradiol were measured in stored serum specimens from men examined in the morning sample of the first phase of NHANES III (1988-1991). (cdc.gov)
  • The most abundant metabolite in fish tissue was the glucuronide of 2'-OH-TCC. (cdc.gov)
  • Estrone glucuronide conjugates of hen egg white lysozyme were prepared by both the mixed-anhydride and active-ester coupling procedures. (kent.ac.uk)
  • The purified conjugate material from the active-ester reaction gave over 90% inhibition of the lytic activity in the presence of an estrone glucuronide antibody. (kent.ac.uk)
  • When used in a homogeneous enzyme immunoassay system the levels of urinary estrone glucuronide encountered in a normal menstrual cycle were easily measured. (kent.ac.uk)
  • A single administered dose of estradiol is absorbed 15% as estrone, 25% as estrone sulfate, 25% as estradiol glucuronide, and 25% as estrone glucuronide. (wikipedia.org)
  • Twenty-eight (28) yellow tablets each containing 90 mcg of levonorgestrel (17α)-(-)13-ethyl-17-hydroxy-18, 19-dinorpregn-4-en-20-yn-3-one, a totally synthetic progestogen, and 20 mcg of ethinyl estradiol, (17α)-19-norpregna-1,3,5(10)-trien-20-yne-3,17-diol. (rxlist.com)
  • RECLIPSEN Tablets provide an oral contraceptive regimen of 21 white round tablets each containing 0.15 mg desogestrel (13-ethyl-11-methylene-18, 19-dinor-17 alpha-pregn-4-en-20-yn-17-ol) and 0.03 mg ethinyl estradiol (19-nor-17 alpha-pregna-1,3,5 (10)-trien-20-yne-3, 17, diol). (druglib.com)
  • Formation of these conjugates, catalyzed by UDP-glucuronosyltransferases (UGTs), decreases the amount of pharmacologically active salicylic acid present. (aspetjournals.org)
  • Uridine diphospho-glucuronosyltransferases (UGTs) inactivate and facilitate the excretion of estrogens to glucuronides (-G), the most abundant circulating estrogen conjugates. (nih.gov)
  • The identity of the conjugated estrogens formed by all known overexpressed UGTs (n = 16) was analyzed by comparison with retention time and mass fragmentation of authentic standards by HPLC tandem mass spectrometry methods. (nih.gov)
  • Estrogen glucuronides can be deglucuronidated into the corresponding free estrogens by β-glucuronidase in tissues that express this enzyme, such as the mammary gland. (wikipedia.org)
  • As a result, estrogen glucuronides have estrogenic activity via conversion into estrogens. (wikipedia.org)
  • The Women's Health Initiative (WHI) study reported increased risks of myocardial infarction, stroke, invasive breast cancer, pulmonary emboli, and deep vein thrombosis in postmenopausal women (50 to 79 years of age) during 5 years of treatment with oral conjugated estrogens (CE 0.625 mg) combined with medroxyprogesterone acetate (MPA 2.5 mg) relative to placebo. (theodora.com)
  • The Women's Health Initiative Memory Study (WHIMS), a substudy of WHI, reported increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 4 years of treatment with oral conjugated estrogens plus medroxyprogesterone acetate relative to placebo. (theodora.com)
  • Other doses of oral conjugated estrogens with medroxyprogesterone acetate, and other combinations and dosage forms of estrogens and progestins were not studied in the WHI clinical trials and, in the absence of comparable data, these risks should be assumed to be similar. (theodora.com)
  • Generally, subfamily UGT1A enzymes conjugate the 3-hydroxyls of estrogens, while the activity of subfamily UGT2B is directed towards 16- and 17-hydroxyls. (helsinki.fi)
  • Formation of estrogen glucuronide conjugates is particularly important with oral estradiol as the percentage of estrogen glucuronide conjugates in circulation is much higher with oral ingestion than with parenteral estradiol. (wikipedia.org)
  • Approximately 7% of estradiol is excreted in the urine as estradiol glucuronide. (wikipedia.org)
  • The ABC transporters MRP2, MRP3, MRP4, and BCRP, as well as several other transporters, have been found to transport estradiol glucuronide out of cells. (wikipedia.org)
  • Estradiol glucuronide has been identified as an agonist of the G protein-coupled estrogen receptor (GPER), a membrane estrogen receptor. (wikipedia.org)
  • This may be involved in estradiol glucuronide-induced cholestasis. (wikipedia.org)
  • Estradiol glucuronide shows about 300-fold lower potency in activating the estrogen receptors relative to estradiol in vitro. (wikipedia.org)
  • Glucuronides are the most abundant estrogen conjugates. (wikipedia.org)
  • The circulating concentrations of estrogen glucuronides are generally more than 10-fold lower than those of estrone sulfate, the most abundant estrogen conjugate in the circulation. (wikipedia.org)
  • We evaluated the effectiveness of seven commercial hydrolytic enzymes to simultaneously hydrolyze N-glucuronides (using the antibacterial triclocarban as example compound) and other conjugates (using select phenols and parabens as examples) by using on-line solid phase extraction-high performance liquid chromatography-isotope dilution-tandem mass spectrometry. (cdc.gov)
  • In contrast when denaturing 7 M urea buffers were used the conjugates eluted in the order of their electrostatic charges and reproducible patterns were obtained which served as an excellent analytical system for lysozyme-steroid glucuronide conjugates. (kent.ac.uk)
  • Developing suitable analytical methods for the concurrent quantification of multiple exposure biomarkers is challenging because optimal conditions for the hydrolysis of such conjugates (e.g. (cdc.gov)
  • Glucuronide Conjugation of Various aglycones in the Liver of Chick Embryos and Chicks. (helsinki.fi)
  • These results highlight the relevance of method validation procedures that include optimizing the hydrolysis of phase II urinary conjugates (e.g., enzyme type and amount used, reaction time, temperature) to quantify accurately and concurrently multiple exposure biomarkers for biomonitoring purposes. (cdc.gov)
  • Following absorption, levonorgestrel is conjugated at the 17β-OH position to form sulfate and to a lesser extent, glucuronide conjugates in plasma. (empr.com)
  • Conjugated NADA accounts for about 90% of the total excretion of NADA. (hmdb.ca)
  • For excretion, most of it gets excreted in feces, while only 20% from urine in the form of glucuronide conjugate. (harcourthealth.com)
  • Ratios of salicylic acid phenolic to acyl glucuronide formation varied more than 12-fold from 0.5 for UGT1A6 to 6.1 for UGT1A1. (aspetjournals.org)
  • 30 units/muL urine) or liquid beta-glucuronidase/arylsulfatase (Helix pomatia, 30 units/muL urine [i.e., 30 muL/100muL urine]) in the presence of 100muL methanol for 100muL urine completely hydrolyzed N-glucuronide triclocarban and the conjugates of several phenols and parabens, without cleaving the ester bond of the parabens to form p-hydroxybenzoic acid. (cdc.gov)
  • The chromatographic behaviour of the reaction mixtures on Mono S columns under non-denaturing conditions was complex as a result of hydrophobic effects and only at pH values above 7.0 did the conjugates elute in the order of their overall charges. (kent.ac.uk)
  • 16179545 ). NADA exists in both free and conjugated (glucuronide) forms. (hmdb.ca)
  • enter the bladder epithelium and re- nary acidity for the hydrolysis of the The carcinogenic activity of ar- act with DNA either directly or after N -hydroxyarylamine N -glucuronides omatic amines in the bladder in esterification. (who.int)
  • Diet questionnaires and fecal samples were collected to compare differences between UA producers and non-producers along with plasma samples at different time points to assess levels of UA and its conjugates between the interventions. (nature.com)
  • The cardiovascular system and central nervous system seem to be the major targets of conjugated quercetin glucuronides circulating in the human bloodstream. (rsc.org)
  • Accordingly, quercetin conjugates exclusively circulate in the human bloodstream and excreted into the urine by the ingestion of quercetin glycoside-containing diet. (rsc.org)
  • Glucuronide conjugates can be split off in waste water treatment plants and generate active substance again (Larsson et al, 1999). (janusinfo.se)