72 II. DIGESTION AND ABSORPTION OF FATS 



(Gr. xn' v , goose) was discovered as early as 1849 by Marsson 400 in goose 

 bile. It is now known to be 3,7-dihydroxycholanic acid. Chenodesoxy- 

 cholic acid Avas isolated from goose bile by Windaus, 401 simultaneously 

 with the preparation of anthropodesoxycholic acid (Gr. avdpuiros, man) 

 from human bile. 402 These two acids were shown to be identical, and the 

 name used earlier, i.e., chenodesoxycholic acid, is now exclusively used for 

 both. It is an isomer of desoxycholic acid. Ursodesoxycholic acid 

 (Latin, ursus, bear), which was first isolated from the bile of the polar 

 bear by Hammarsten in 1901 , 403 as the taurine conjugate, and which was 

 later studied by Shoda, 404 has been shown to be a stereoisomer of chenodes- 

 oxycholic acid. 405 Lett re 4 " 6 found that the isomerism occurs on C7; the 

 hydroxyl on this carbon atom is cis to the do-methyl in chenodesoxycholic 

 acid and trans to the Ci -methyl group in ursodesoxycholic acid. Ursodes- 

 oxycholic acid has recently been shown to occur in conjugation with 

 glycine, 407 as well as with taurine. 404 Brigl and Benedict 408 have reported 

 the presence of an isomer of glycocholic acid, namely glyconutriacholic 

 acid, in the bile of the water-rat, or swamp beaver (Myocaster coypus). 

 The finding of nutriacholic acid has recently been confirmed by Haslewood 

 andWootton. 409 



3-Hydroxy-6-ketoallocholanic acid is an example of a bile acid containing 

 a ketone group. It was first isolated from hog bile by Fernholz, 410 and its 

 presence in the bile of this species has been confirmed by a number of other 

 workers. 4U ~ 414 Trickey 416 has recently reported that the bile acids of 

 hog bile contain approximately 20% of keto acids, most of which consist 

 of 3a-hydroxy-6-ketoallocholanic acid. In reviewing this work, Schoen- 

 heimer and Evans 416 suggested that the keto acid probably exists in hog 

 bile as the cholanic acid derivative, but that its conversion to the alio 



400 T. Marsson, Arch. Pharm., 108 ([2], 58) 138-148 (1849); Ann., 72, 317-318 (1849). 



401 A. Windaus, A. Bohne, and E. Schwarzkopf, Z. physiol. Chem., 140, 177-185 (1924). 



402 H. Wieland and G. Reverv, Z. physiol. Chem., 140, 186-202 (1924). 



403 O. Hammarsten, Z. physiol. Chem., 82, 435-466 (1901); 36, 525-555 (1901). 



404 M. Shoda, /. Biochem. (Japan), 7, 505-517 (1927). 



405 T. Iwasaki, Z. physiol. Chem., 244, 181-193 (1936). 



406 H. LettrS, Ber., 68, 766-767 (1935). 



407 S. Miyazi, Z. physiol. Chem., 250, 34-36 (1937). 



408 P. Brigl and O. Benedict, Z. physiol. Chem., 220, 106-112 (1933). 



409 G. A. D. Haslewood and V. Wootton, Biochem. J., 47, 584-597 (1950). 



410 E. Fernholz, Z. phi/siol. Chem., 232, 202-205 (1935). 



411 M. Anchel and R. Schoenheimer, J. Biol. Chem., 124, 609-611 (1938). 



412 R. Schoenheimer and C. G. Johnston, /. Biol. Chem., 120, 499-501 (1937). 



413 G. Sugiyama, J. Biochem. {Japan), 25, 157-165 (1937). 



414 1. Ido and R. Sakurai, J. Biochem. (Japan), 29, 51-55 (1939). 



415 E. B. Trickey, J. Am. Chem. Soc, 72, 3474-3477 (1950). 



416 R. Schoenheimer and E. A. Evans, Jr., Ann. Rev. Biochem., 6, 139-162 (1937). 



