Glucuronic acid isolation, from urine

Aglycons of the Conjugates of D-Glucuronic Acid Isolated from Urine... 

Compounds known to behave in this way in vivo are listed in recent reviews in this Series.1 2 The structures of some of the /3-D-glucopyranosiduronic acids isolated from urine have been proved by chemical synthesis.3 A few similar derivatives of flavones and triterpenes have been isolated from plants. D-Glucuronic acid also occurs in mammalian tissues as a constituent of acid mucopolysaccharides (aminodeoxypolysaccharides, containing uronic acid), such as hyaluronic acid, chondroitinsulfate, and heparin,4 and it is a direct precursor of L-ascorbic acid in plants and mammals.6 It is present in many of the plant polysaccharides classified as hemicelluloses6 and gums,7 and it has also been found in certain bacterial polysaccharides.4... 

Free dihydrodiol metabolites have been isolated from urine, following the administration of phenanthrene119 and chlorobenzene.120 The yields are low because, under mildly acidic conditions and gentle heating, the diols are easily dehydrated to phenols, or their D-glucuronic conjugates may be hydrolyzed and the aglycons reduced to the parent hydrocarbons. As a consequence, labile diols may be the true excretion products of many hydrocarbons whose phenolic derivatives have been isolated from urine, such as 1,2,5,6-dibenzanthracene, 1,2-benzanthracene, 3,4-benzopyrene, and 9,10-dimethyl-l,2-benzanthracene.121... 

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. 

D-Glucuronic acid, a-linked to a glycerol unit, has been found as a constituent of ardiscrenolide E, a triterpenoid pentasaccharide from a Chinese shrub. 7 Both the phenolic and acyl p-D-glucuronides of salicylic acid, and the phenolic P-D-glucuionide of salicyluric acid (N-salicylyl-glycine) have been isolated from human urine by preparative h.p.l.c their stability in aqueous solution, and towards glucuronidase, was assessed. ... 

Analysis by a naphthoresorcinol method gives the total hexuronic acids. Glucuronic acid is the most common hexuronic acid found in nature and appears to be the only one found in animal material. Thus, results obtained from urines by the naphthoresorcinol method may be reasonably assumed to refer to glucuronic acid. It is desirable, however, to confirm the identity of the acid, using paper chromatography (66), or by the isolation and preparation of a derivative, e. g., Levvy (60). 

Dogs excrete p-hydroxybenzaldehyde (XLVI) as p-glucuronosidobenzoyl glucuronoside, p-hydroxyhippuric acid and possibly free p-hydroxybenzoic acid (67, 351). In the case of rabbits, however, p-glucuronosidobenzalde-hyde has been isolated from the urine as the 2,4-dinitrophenylhydrazone and it appeared probable that conjugation of the phenolic hydroxyl with glucuronic acid preceded oxidation of the aldehyde group (147). 

A small amount of a complex of 4-hydroxyantipyrine with glucuronic acid can be isolated from the urine after ingestion of pyramidone (138). The main products of pyramidone metabolism in man are 4-acetylamino-antipyrine and 4-aminoantipyrine and these two compounds account for about 50 per cent of a 0.5 g. dose. Isolation of a glucuronoside of unknown constitution also was reported by Jaffe (184). In addition the latter investigator isolated rubazonic acid (LXVII) (184) and antipyrylurea (LXVIII) (185). These latter two compounds may have been artifacts (447). 

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