HOLE OF BILE IN LIPID ABSORPTION 77 



the North American bullfrog (Rana catesbiana). Kuroda 447 isolated three 

 kinds of tetrahydroxyhomocholane sulfate from the bile of Rana catesbiana 

 Shaw. Upon hydrolysis, three different trihydroxyhomocholenes (C25H42O3) 

 melting at 177°, 196°, and 238°C, respectively, were obtained. Each of 

 the homocholenes had one double bond and an a-configu ration of the hy- 

 droxyl group on C3. The sulfate radical was shown to be combined with a 

 tertiary hydroxyl. Komatsubara and Nakanura 448 isolated two isomeric 

 C 2 6-acids from the spotted frog (Rana nigromaculata nigromaculata) , 

 namely a- and /3-trihydroxybisnorsterocholanic acids, which also have an 

 empirical formula of C26H44O5. These acids were proved to exist partly as 

 free acids and, in a larger proportion, conjugated with taurine. 



Haslewood 444 reported that the bile of the North American alligator 

 (Alligator ?nississippiensis) contained a mixture of acids, one of which had 

 the formula, C27H46O5, and a melting point 449 of 172°C. Bridgewater and 

 Haslewood 449 converted this naturally occurring acid to "stem acid," 

 C27H 46 2 , which had a melting point of 104°C. These workers 449 succeeded in 

 partially synthesizing this latter acid from cholamc acid. Another atypical 

 bile acid derivative, namely the lactone of trihydroxysterocholanic acid 

 (C28H 4 fi0 5 ), was isolated by Kim 450 from the bile of the European pond- 

 tortoise (Emys orbicularis) ; it is isomeric with trihydroxybufosterocholenic 

 acid. The finding that the same atypical acids occur in the bile of these 

 amphibia as in the case of frogs and toads suggests that they are of an 

 equally primitive evolutionary type. 



The type of bile acids, or the component in bile corresponding to the acids, 

 differs in the elasmobranch and in the teleost fishes. Instead of the ordi- 

 nary bile acids found in the Teleostei, acids having empirical formulas of 

 C27H46O6 or C28H 48 06 have been reported in a shark from the Chosen Sea 451 ; 

 in the case of the blue skate (Raia batis), and of the grey Atlantic dogfish 

 (Squalus acanthias), a polyhydroxy-derivative, scymnol, was found in 

 place of the bile acids 452 ; it was conjugated with sulfuric acid. Hammar- 

 sten 453 had reported the presence of 'V and "/3" scymnol in the bile of 

 a viviparous species of Greenland shark (Scymnus (Laemargus) borealis 

 Scoresby, also given as Somniosns microccphalus, Schneider) a number of 

 years earlier. Although the structure of scymnol has been the object of a 



447 M. Kuroda, J. Biochem. {Japan), 40, 109-174 (1953). 



"* T. Komatsubara and H. Nakanura, ./. Biochem. (Japan), 39, AbsL, 8 (1952). 



449 R. J. Bridgewater and G. A. D. Haslewood, Biochem. J., 51, xxiv (1952). 



450 C. H. Kim, J. Biochem. {Japan), 30, 247-249 (1939). 

 461 K. Ohta, /. Biochem. (Japan), 29, 241-245 (1939). 

 452 J. W. Cook, Nature, U7, 388 (1941). 



46 »0. Ilammarsten, Z. physiol. Chem., 24, 322-350 (1898). 



