Glucuronic acid in urine

Glucose, mandelamine, and hydrochlorothorazide decrease the amount of estriol found when acid hydrolysis is used to release estriol from its conjugate with glucuronic acid in urine. The destruction of estriol in diabetic urine can be monitored by the inclusion of internal standards of labeled estriol glucuronide and reduced by prior dilution of the urine. When glucuronidase is used to release the estriol, the results are not affected when glucose of diabetic urine is present. When this is done the internal standard is not necessary. 

Naphthoresorcinol NSC 115890. Inhibitor of prostaglandin synthase. Used to assay sugars, oils and glucuronic acid in urine. White leaflets mp = 123.5° Xm = 214, 236, 287, 336 nm (MeOH) slightly soluble in Me2CO, CeHe, ligroin, soluble in H2O, EtOH, Et20, AcOH. 

A method has been developed for the measurement of D-glucuronic acid in urine based on a reaction with tetraborate in the presence of sulphuric acid and 3-hydroxydiphenyl. ° Both free and bound acids can be determined more accurately than by the commonly used decarboxylation and resorcinol methods. 

P2. Pollack, R. L., and Eades, C. H., Glucuronic acid conjugates of aspartic and glutamic acids in urine. Science 119, 510-511 (1954). 

Mai ins et al. (15) showed by TLC that rainbow trout exposed to l C-labeled naphthalene excrete 1-naphthyl glucuronic acid in the urine almost exclusively. Only 1% of the total radioactivity of the urine was in the form of non-conjugated derivatives. 

Chloramphenicol is completely absorbed after oral administration, bound to plasma protein (approximately 60%) and widely distributed in body. It crosses the blood-brain and placental barrier and shows its presence in CSF, bile and milk. It is conjugated with glucuronic acid in liver and excreted in urine. Small amount is excreted in urine in unchanged form. 

Plasma and urine samples from atherosclerotic and control rats were comparatively analyzed by ultrafast liquid chromatography coupled with ion trap-time-of-flight (IT-TOF) MS (UFLC-IT/TOF-MS) (16). They identified 12 metabolites in rat plasma and 8 metabolites in rat urine as potential biomarkers. Concentrations of leucine, phenylalanine, tryptophan, acetylcar-nitine, butyrylcamitine, propionylcamitine, and spermine in plasma and 3-0-methyl-dopa, ethyl /V2-acety I -1. -argininate, leucylproline, glucuronate, A(6)-(A-threonylcarbonyl)-adenosine, and methyl-hippuric acid in urine were decreased in atherosclerosis rats ursodeoxycholic acid, chenodeoxycholic acid, LPC (06 0), LPC (08 0), and LPC (08 1) in plasma and hippuric acid in urine were increased in atherosclerosis rats. The altered metabolites demonstrated abnormal metabolism of phenylalanine, tryptophan, bile acids, and amino acids. Lysophosphatidylcholine (LPC) plays an important role in inflammation and cell proliferation, which shows a relationship between LPC in the progress of atherosclerosis and other inflammatory diseases. 

Oxidation of glucose at C6 produces glucuronic acid. In the body, a common method for metabolizing drugs is to attach glucuronic acid. The resulting glucuronide derivative is water-soluble and easily excreted in the urine. 

Terpenes are oxidized by cytochrome P450, conjugated principally with glucuronic acid in the liver, and are excreted by the kidney. Part of inhaled turpentine is eliminated unchanged in expired air and in urine, but most is metabolized and excreted in urine conjugated with glucuronic acid. The excretory product of turpentine has a characteristic odor of violets. 

Approximately 65% of furosemide is excreted unchanged in the urine, and the remainder is conjugated to glucuronic acid in the kidney. Accordingly, in patients with renal, but not fiver, disease, the elimination half-life of furosemide is prolonged. In contrast, bumetanide and torsemide have significant hepatic metabolism, so the elimination half-lives of these loop diuretics are prolonged by liver, but not renal, disease. 

Procedure. Urine is diluted so as to contain not more than 0.04 mg./ml. of glucuronic acid. Diluted urine (2 ml.), hydrochloric acid (4 ml.), and naphthoresorcinol (2 ml) in a test tube (13 x 150 mm.) are heated in boiling water for 2 hours. Evaporation is reduced by a "cold finger condenser placed in the top of the tube. The tube and contents are then cooled in cold water. n-Butanol (5 ml.) is added, the tube is corked, and is shaken well and left to stand for 3 minutes for air bubbles to disperse. The absorption value is then read within 5 minutes in a photoelectric absorptiometer using an Ilford Spectrum Orange 607 filter. The calibration curve can be constructed using 0.2 to 2 ml. of glucurone solution made up to 2 ml. with water. 

In conclusion difenpiramide is hydrolyzed in the body to biphenylylacetic acid and a-aminopyridine. Biphenyly lacetic acid is metabolized to -hydroxybiphenylylacetic acid by hydroxylation of the biphenyl group in the p-position. Biphenylylacetic acid is pharmacologically active, while -hydroxybiphenylylacetic acid is inactive. An amount of these two acids made water soluble by conjugation (mainly with glucuronic acid, in part with amino acids) are excreted in the urine. Biphenylylacetic acid is found in... 

Optical rotation occasionally has been used as an indication of the presence of conjugated glucuronic acid in the urine. While the free acid is dextrorotatory, its conjugation products are generally levorotatory. If urine known to contain no albumin, /3-hydroxybutryic acid, fructose or cystine is found to be levorotatory after it has been clarified with lead acetate in acid medium and then filtered, conjugated glucuronic acid is probably present. 

Deichmann and Dierker (72) found that the amount of glucuronic acid in serum or plasma varied between 0.4 and 2.5 mg. per 100 ml. in man, rabbits or rats. In rabbits or rats, this value was increased up to as high as 120 mg. per 100 ml. following administration of 2-methyl-2,4-pentandiol or cyclohexanone the amount in the plasma paralleled that excreted in the urine. 

Formanilide was thought to be excreted by dogs as p-aminophenol (203). Benzoxazolone also was isolated, but Williams (447) believed it to be an artifact formed from o-aminophenol. He assumed that the formyl group was removed in the course of metabolism and that the resulting aniline was oxidized in both the ortho and para positions. The presence of glucuronic acid in the urine was indicated (203). The main metabolic product in rabbits was p-aminophenol. 

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