Glucuronides in urine

The uronic acid pathway is the source of glucuronic acid for conjugation of many endogenous and exogenous substances before excretion as glucuronides in urine and bile. 

G Barnard, F. Kohen, H. Mikola, and T. Lovgren, Measurement of estrone-3-glucuronide in urine by rapid, homogeneous time-resolved fluoroimmunoassay, Clin. Chem. 35, 555-559 (1989). 

B3. Barnard, G., Amir-Zaltsman, Y, Lichter, S., Gayer, B., and Kohen, F., The measurement of oestrone-3-glucuronide in urine by non-competitive idiometric assay. J. Steroid Biochem. Mol. Biol. 55, 107-114 (1995). 

Miners et al. reported an ethnic difference in the His268Tyr (802 C>T) variant (99). In 91 Caucasians, the allele frequency for UGT2B7 2 (802 C>T) was 0.482 versus 0.268 for 84 Japanese subjects. Patel et al. reported a potential polymorphism in the ratio of (R)- and (iS )-oxazepam glucuronides in urine (100). While (J )-oxazepam is a substrate for UGT2B7, the turnover is very low and there was no difference between the UGT2B7 variants in terms of stereoselectivity (99). More recent data indicates that (.Sj-oxazepam is a UGT2B17 substrate. 

Bile alcohols are polyhydroxy C27 sterols that serve as intermediates in the biosjmthesis of cholic acid and chenodeoxycholic acid from cholesterol (1, 2). Recently several studies have shown that increased amounts of bile alcohols namely 27-nor-5p-cholestane-3a,7a,12a,24, 25-pentol and 5P-cholestane-3a, 7a,12a,25,26-pentol are excreted (as glucuronides in urine of patients with liver diseases such as primary biliary cirrhosis (3), liver cirrhosis (4, 5) and a-antitrypsin deficiency (6). Ichimiya et. al., described the occurrence of 5P-cholestane-3a,7a,12a,26,27-pentol (5P-cyprinol) and 5P-cholestane-3a,7a,... 

A7. Alme, B., and Sjdvall, J., Analysis of bile acid glucuronides in urine. Identification of 3a,6a,12a-trihydroxy-5 -cholanoic add.. Steroid Biochem. 13, 907-916 (1980). 

W. Weimmann, P. Schaefer, et al.. Confirmatory analysis of ethyl glucuronide in urine by liquid chromatography/electrospray-tandem mass spectrometry, J. Am. Soc. Mass Spectrom. 15, 188-193 (2004). 

Back, P., Spaczynski, K., and Gerok, W. Bile Salt Glucuronides in Urine Hoppe-Seyler s Z. Physiol. Chem. 355... 

The metabolic fate of sinapic acid in humans as well as its derivatives, which represent the naturally occurring form of sinapic acid, has not been studied yet and remains uncertain. But in a study on the metabolic fate of polyphenols from a polyphenol-rich diet, small amounts of sinapic acid were detected in urine post 3-glucuronidase treatment during a 5-day feeding period [37]. This presence of sinapic acid (as glucuronide) in urine implies its bioavailability from the diet in humans and a metabolic fate of dietary sinapic acid derivatives similar to that of other hydroxycinnamic acid derivatives such as chlorogenic acid. 

An attractive appearing reversed-phase h.p.l.c. method, in which ionization of sugar acids is prevented by use of acidic eluant fe.a.. pH 2), has been used for analysis with fluorometric detection of estriol 3- and 16-glucuronides in urine of nonpregnant women after initial concentration onto graphitized carbon black cartridges," and of L-ascorbic acid in fruit juice. 

A test for glucuronides in urine, based on their reaction with naphthoresorcinol to give a red colour. 

In a second study, subjects were administered 25 pg BPA, and unconjugated and conjugated BPA were measured in urine at 0, 1, 3, 5, and 7 h after exposure (Volkel et al. 2005). The authors concluded that due to the rapid and complete elimination of BPA in humans as BPA-glucuronide in urine (Volkel et al. 2002), that human exposure to BPA is less than 2.3 pg/person per day (based on a volume... 

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