CONJUGATED GLUCURONIC ACIDS. 751 



diabetes and found that the above expectation was not realized. Although 

 large quantities of campho-glucuronic acid were excreted, the sugar 

 excretion was only slightly diminished and not in proportion to the 

 quantity of conjugated glucuronate excreted. These negative results 

 are contradicted by the positive results obtained by PAUL MAYER. 1 

 Rabbits normally convert almost all the camphor introduced into con- 

 jugated glucuronic acid. MAYER claims that if we allow a rabbit to 

 starve several days, the animal becomes so poor in the mother-substance 

 (glycogen) yielding the glucuronic acid that the introduction of camphor 

 only brings about an elimination of small quantities of glucuronic acid. 

 By the simultaneous administration of camphor and glucose while 

 starvation is going on, the elimination of glucuronic acid rises again to 

 the same height as it was before the starvation period. This shows that 

 the sugar had conjugated itself with the camphor as glucuronic acid. 

 HiLDEBRANDT 2 has also made experiments showing that glucuronic acid 

 can very likely be formed from sugar. The observations of MAYER are 

 not substantiated by the recent investigations of FENYVESSY, S and the 

 observers do not agree on this question. 



The conjugated glucuronic acids are formed, based upon the investi- 

 gations of SUNDWIK, FISCHER and PILOTY,* by a combination taking 

 place first between the conjugator and the glucose by means of the alde- 

 hyde group, and then the end alcohol group, CH^OH, is oxidized to COOH. 

 The conjugated glucuronic acids, at least in most cases, seem to be con- 

 structed after the glucoside type, a view which has received further 

 support by the synthesis of phenolglucuronic acid and euxanthonglu- 

 curonic acids by NEUBERG and NEIMANN. S Based upon their cleavage 

 (as far as they have been investigated) by kephir lactase and emulsin, 

 but not by yeast lactase (NEUBERG and WOHLGEMUTH 6 ), the conjugated 

 glucuronic acids must belong to the /3-series of glucosides. We also 

 know of certain conjugated glucuronates that are constructed upon the 

 ester type, namely, the dimethylaminobenzoicglucuronate, discovered 

 by JAFFE and also the benzoicglucuronic acid, after feeding benzoic 

 acid (MAGNUS-LEVY). 7 



According to the body with which they are conjugated the glucuronates 

 vary in behavior. On taking up water they split into glucuronic acid 



1 Zeitschr. f . klin. Med., 47. 



2 Arch. f. exp. Path. u. Pharm., 44. 



3 See Maly's Jahresber., 34. 



4 E. Sundwik, Akademische Abhandlung Helsingfors, 1886; see also Maly's Jahr- 

 esber., 16, 76; Fischer and Piloty, Ber. d. d. chem. Gesellsch., 24. 

 6 Zeitschr. f. physiol. Chem., 44. 



6 See Neuberg, Ergebnisse der Physiologic, Bd. 3, Abt. 1, 444. 



7 Jaffe, Zeitschr. f. physiol. Chem., 43; Magnus-Levy, Bioch. Zeitschr., 6. 



