352 



IV. WAXES, HTOHER AL0OHOT>S, ETC. 



intermediate. Comparative data on the 8- and e-sitosterol are not at 

 present available. 



All three a-isomers have been shown to be present in wheat germ oil,-^^-^^* 

 while rye germ oil has been shown to contain oci- and a.-j-sitosterol, as well 

 as the 0- and 7-forms.---^ Pure /3-sitosterol has been prepared from cotton- 

 seed oil, which contains chiefly this type of sitosterol. '■^^* The seeds of the 

 sweet-scented shrub (Calycanthus floridus) also contain almost exclusively 

 the j8-isomer,-^^ while soybean and wheat germ oils contain principally 

 7-sitosterol. /S-Sitosterol has been shown to be present in the kidney bean 

 {Phaseolus vulgaris), along with stigmasterol.^®'' Chincol, which is a sterol 

 from cinchona bark, appears to be a |8-sitosterol.-^^ 



Sitosterol mixtures as found in plants crystallize from dilute alcohol with 

 one molecule of water of crystallization. The shiny white leaf-like crystals 

 are very similar to those of cholesterol. Fine white needles are produced 

 when the sterol is crystallized from ether. The sitosterols give a difficultly 

 soluble precipitate with digitonin. Characteristic products formed from 

 sitosterols are the acetates, benzoates, and 3,5-dinitrobenzoates. The 

 melting points and specific rotations of these esters show considerable 

 variation in the different forms of the sitosterols (Table 6). 



b'. Stigmasterol : Stigmasterol frequently occurs with sitosterol and is 

 second in importance of the products classed as phytosterols. Only one 



CH, 



I 



I ^ 

 -CH = CHC-CH— CHj 



I I 

 H CH, 



Stigmasterol 



stigmasterol has been reported, and this has been shown^-^ to have an 

 empirical formula of C29H48O, with double bonds at the 5,6 and 22,23 posi- 

 tions and with an ethyl group at C24.'^^^~-^'' The conversion of stigmasterol 



263 S. W. Glover and H. A. Schuette, J. Am. Chem. Soc, 61, 1901-1903 (1939). 

 26* E. S. Waliis and P. N. Chakravorty. /. Org. Chem.., 2, 335-340 (1937). 



265 J. W. Cook and M. F. C. Paige, /. Chem. Soc, 19U, 336-337. 



266 A. C. Ott and C. D. Ball, J. Am. Chetn. Soc, 66, 489-491 (1944). 



267 W. Dirscherl, Z. physiol. Chem., 257, 239-245 (1939). 



268 A. Guiteras, Z. physiol. Chem., 214, 89-90 (1933). 



269 E. Fernholz, Ann., 507, 128-138 (1933). 

 2TO E. Fernholz, Ann., 508, 215-224 (1934). 



