HOLE OF BILE IN LIPID ABSORPTION 95 



desoxycholic acid and cholesterol combination dialyzed through a collodion 

 membrane. 506 The passage of cholesterol through plates of agar and gelatin 

 was shown to be aided by bile salts, 518 although Breusch 519 does not sub- 

 scribe to the idea that cholesterol in bile salts can diffuse. Schonheimer 520 

 was able to demonstrate that the speed of absorption of cholesterol from the 

 intestines of mice was accelerated by the presence of desoxycholic acid, 

 while Loeffler 521 found that cholesterol storage in the liver of rabbits was 

 greatly increased when cholesterol was fed along with the bile acids. 



In addition to fatty acids and cholesterol, many other organic compounds 

 can combine with desoxycholic acid. Sobotka 398 named these compounds 

 ''acholic" constituents of choleic acids. This group includes aliphatic 

 alcohols, ethers, ketones, esters, and hydrocarbons, as well as cyclic alco- 

 hols, ketones, and hydrocarbons. Huntress and Phillips 522 described 34 

 paraffin hydrocarbons which form with desoxycholic acid (in methanol) 

 definite molecular compounds which are easily reproducible. It was found 

 that one mole of hydrocarbon is combined with 2 to 8 molecules of the bile 

 acids. 



A combination of /8-carotene and desoxycholic acid in a molecular ratio 

 of 1 : 1 has recently been prepared from an alcohol and carbon tetrachloride 

 solution. 523 Almquist and Klose 524 described a choleic acid compound of 

 vitamin K, melting at 185°C. and containing about 10% of the acholic 

 derivative; the bile salt : vitamin K ratio was reported to be about 8: 1 in 

 this preparation. Stable additive compounds have also been prepared 

 with alkaloids. It is therefore obvious that a large number of choleic 

 acids exist, These vary in composition not only according to the acholic 

 constituent but also in the ratio of desoxycholic acid to the acholic com- 

 ponent in the molecule. The term, choleic acid, should therefore be con- 

 sidered as referring solely to a group of compounds rather than to a specific 

 substance. The choleic acids containing palmitic, stearic, or oleic acids 

 which have been prepared from bile are sometimes designated as "natural 

 choleic acids." A list of the choleic acids, including their melting points 

 and coordination numbers, is given in Tables 12 to 14. 



(d) Coordination Number. It was assumed by Wieland and Sorge 506 

 that the choleic acids contain one bile acid for each — CH 2 CH 2 — unit. 



618 O. von Furth and R. Scholl, Biochem. Z., 222, 430-456 (1930). 



619 F. L. Breusch, Biochem. Z., 293, 280-294 (1937). 



520 R. Schonheimer, Biochem. Z., 147, 258-263 (1924). 



521 K. Loeffler, Z. physiol. Chem., 178, 186-191 (1928). 



522 E. H. Huntress and R. F. Phillips, /. Am. Chem. Soc, 71, 458-460 (194!)). 



523 G. Milazzo and G. Giacomello, Gazz. chim. Hal., 70, 73-86 (1939). 



524 H. J. Almquist and A. A. Klose, J. Am. Chem. Soc, 61, 745-746 (1939). 



