ROLE OF BILE IN LIPID ABSORPTION 79 



(?) 



H OH H 3 C CH 2 OH 

 (X) 3,6,12,24-Tetrahydroxynorsterocholanic Arid 



Komatsubara and Nakanura 44 * isolated a new neutral bile acid con- 

 jugated with sulfuric acid, having the empirical formula CsnHssOsSC^Na, 

 and melting at 192°C, from the bile of the eel-tailed loach or weather-fish 

 (Misyurnus anguillicaiulatus) . On hydrolysis, this acid gave rise to a 

 hexahydrosteroid, CsoHseOe, Avhich melted at 242-243°C. 



Sapocholic acid, which is one of the weaker acids in ox bile, was first 

 assigned the formula C29H46O3 by Wieland and Hanke, 464 but this was later 

 revised to C30H48O3 by Wieland and Seibert. 465 It is now believed that 

 sapocholic acid is not a bile acid but rather a triterpene related to hedera- 

 genin and oleanic acid. It probably is of dietary origin. 464 Pearlman 466 

 identified "compound B," which occurs occasionally in ox bile, as allo- 

 pregnandiol-3(0) ,20(0) . 



b. Conjugation of the Bile Acids. The cholanic acids are usually con- 

 jugated with glycine, NH 2 CH 2 COOH, or taurine, NH 2 CH 2 CH 2 S0 2 OH. 

 The hog is the only animal in which no taurine is found, and glycine is the 

 sole amino acid conjugated with the cholanic acid. The glyco-acids pre- 

 dominate over the tauro-acids in man, cattle, kangaroo, hippopotamus, 

 and musk-ox. 467 On the other hand, the bile acids of all other species 

 contain a much larger proportion of the tauro-derivatives. Bensch, 468 as 

 early as 1848, reported that the sulfur of crude bile salts exceeds 5%. 

 Pure taurocholic acids have a theoretical content of only about 6% of 

 sulfur. Thus, all carnivorous animals belong in the tauro-group, and 

 many herbivorous and omnivorus animals are also included in this cate- 

 gory. 467 



The presence of bile acids in a non-conjugated form has been reported 

 in several instances. As early as 1850, Enderlin 469 discovered the presence 



484 H. Wieland and G. Hanke, Z. physiol. Chem., 241, 93-99 (1936). 

 486 H. Wieland and W. Seibert, Z. physiol. Chem., 262, 1-19 (1939). 



466 W. H. Pearlman, J. Biol. Chem., 166, 473-476 (1946). 



467 H. Sobotka, Physiological Chemistry of the Bile, Williams and Wilkins. Baltimore, 

 1937. 



468 A. Bensch, Ann., 65, 194-203 (1848). 



469 C. P^nderlin, Ann., 75, 162-165 (1850). 



