CONJUGATED GLUCURONIC ACIDS. 817 



toses. JoLLES 1 considers the preparation of the osazone as a specially conclusive 

 test and the distillation of the osazone with hydrochloric acid and testing the 

 distillate with BIAL'S reagent. 



ROSENBERGER 2 believes he has detected a heptose in the urine in a case of 

 diabetes. According to him and to GEELMUYDEN 3 probably different varieties 

 of sugar, which are not well known, can possibly occur in urine of diabetics. 



Conjugated Glucuronic Acids. Certain conjugated glucuronic acids 

 such as menthol- and turpentine-glucuronic acid may spontaneously 

 decompose in the urine, and in this case they may readily lead to a con- 

 fusion with pentoses. The urine should always be fresh as possible 

 for these examinations. 



A confusion of the glucuronic acids, which have a reducing power on 

 copper or bismuth solutions, with glucose and fructose, can be pre- 

 vented by the fermentation test. They may also be distinguished from 

 glucose by their optical behavior, as the conjugated glucuronic acids 

 are levogyrate. On boiling with an acid, dextrorotatory glucuronic acid 

 is produced and the levorotation is changed to dextrorotation. 



The conjugated glucuronic acids, like the pentoses, give the phloro- 

 glucin-hydrochloric-acid test. On the contrary they do not give the 

 orcin test directly, but only after cleavage with the setting free of glucuronic 

 acid. On using BIAL'S reagent no mistaking for pentoses occurs, although 

 this statement requires further substantiation. The pentoses may also 

 be isolated and identified by their osazones. Certain readily decomposable 

 glucuronic acids can here give phenylhydrazine compounds. In order to 

 detect glucuronic acid in the osazone precipitate, we can, as suggested 

 by NEUBERG and SANEYOsm 4 take a knife point (about 8 milligrams) 

 of the precipitate, dissolve in 4 cc. strong hydrochloric acid, dilute with 

 4-cc. water, heat to boiling, add at least 0.1 gram naphthoresorcin, warm 

 for | minute, allow to slowly cool to 50 and shake with benzene. In the 

 presence of glucuronic acid the benzene solution is violet with an absorp- 

 tion in the yellowish-green. 



The occurrence of conjugated glucuronic acids in the urine is shown 

 when the urine does not give the orcin-hydrochloric-acid reaction directly, 

 but only after boiling with the acid. The naphthoresorcin reaction, 

 as suggested by TOLLENS, can also be used. To 5 cc. urine add 0.5 cc. 

 of a 1 per cent alcoholic solution of naphthoresorcin and 5 cc. hydro- 

 chloric acid (sp.gr. 1.19), boil for one minute, allow to stand four minutes, 



1 Jolles, Bioch. Zeitschr., 2, Centralbl. f. inn. Med., 1907 and 1912, and Zeitschr. 

 f. anal. Chem., 46. 



2 Zeitschr. f. physiol. Chem., 49. 



3 Rosenberger, Centralbl. f. inn. Med., 28; Geelmuyden, Zeitschr. f. klin. Med., 

 58, 63, and 70. 



4 Bioch. Zeitschr., 36. 



