348 IV. WAXES, HIGHER ALCOHOLS, ETC. 



Bombicesterol has been reported as obtainable from the pupae of the 

 silkworm {Bombyx mori), while stellasterol has been prepared from the 

 testicles of echinoderms and asteroids^*" as well as from the eggs of the 

 starfish (Asterias forbesi) .-'^^'^'^^ Bombicesterol is apparently the only 

 animal sterol (except dihydrocholesterol) which has no double bond be- 

 tween Cs and Ce. It is also distinguished by being the only sterol of the 

 C28 series in the animal group, except for ergosterol in the case of the earth- 

 worm, and ostreasterol in the oyster. Another compound of this group, 

 called microcionasterol, has been prepared""*^ from the sponge {Microciona 

 prolijera), while still another sterol, actiniasterol, which has two double 

 bonds, has been separated from the sea anemone (Anemonia sulcata). ^^^ 



(e) Occurrence and Properties of Phytosterols. The presence in plants of 

 sterols which are different from cholesterol has long been recognized. Until 

 recently, all non-animal sterols have been classed as phytosterols. How- 

 ever, with a more complete appraisal of the chemical nature of the com- 

 pounds in different plant forms, it has now become evident that the higher 

 plants (phanerogams) contain sterols which are quite different from those 

 found in lower plant forms (cryptogams) . The term phy tosterol has been 

 retained for the sterols from the higher plants, while those from the cryp- 

 togams are classed as mycosterols. 



Hesse, ^^^ in 1878, first prepared a plant sterol from Calabar beans and 

 from peas, although Beneke^''^'^^^ had previously separated a sterol from 

 peas which he called cholesterine. Hesse recognized that this sterol dif- 

 fered from cholesterol, although he believed that it was isomeric with it. 

 Because of its wide distribution in the plant kingdom, it was given the 

 name, "phytosterin." Actually, the product which Hesse prepared was a 

 mixture of sterols which Windaus and Hauth^" separated into sitosterol 

 and stigmasterol. It has only recently been shown that the empirical 

 formula for sitosteroF^^-^^^ is C29H49OH, and that for stigmasteroP** is 

 C27H47OH. Neither of these can, therefore, be isomeric with cholesterol. 



a'. Sitosterols: Sitosterol is the most widely distributed of the phyto- 

 sterols. It occurs in an especially high concentration in corn, wheat germ, 

 and soybean oils. Ueno and Yamasaki-"* found Koryan corn oil {Sorghum 

 vulgare) an excellent source of sitosterol, which can be readily purified, as no 



"" A. Kossel and S. Edlbacher, Z. phijsiol. Chem., 94, 264-283 (1915). 



2" I. H. Page, J. Biol. Chem., 57, 471-476 (1923). 



"2 W. Bergmann and H. A. Stansbury, Jr., J. Org. Chem., 9, 281-289 (1944). 



2" W. Bergmann and T. B. Johnson, Z. phijsiol. Chem., 222, 220-226 (1934). 



•^'^ E. Klenk and W. Diebold, Z. physiol. Chem., 236, 141-144 (1935). 



246 jr_ \\r_ Beneke, Studien iiber das Vorkommen, die Verbreitung und die Function von 

 Gallenbestandtheilen in den thierischen and pflanzlichen Organismen, -Rickert, Giessen, 

 1862. 



246 G. M. R. Beneke, Aim., 122, 249-255 (1862). 



2" H. Sandqvist and E. Bengtsson, Ber., 64, 2167-2171 (1931). 



2^» A. Windaus, F. v. Werder, and B. Gschaider, Ber., 65, 1006-1009 (1932). 



2« H. Sandqvist and J. Gorton, Ber., 63, 1935-1938 (1930). 



