NATURAL WAXES 361 



Fucosterol is isomeric with stigmasterol and yields stigmastanol on hy- 

 drogenation.^^' One unsaturated linkage is found between Cs and Ce. 

 The empirical formula is C29H48O. It melts at 124 °C. and has a specific 

 rotation of —38.4°. Fucosterol forms a difficultly soluble digitonide. 



d'. Zymosterol: A second sterol^'* which occurs in yeast is zymosterol 

 (C27H4s6h),^i« which has two double bonds.'*-" It melts at 110°C. and has 

 a specific rotation of +47.3°. It has been identified as A^'^*'-^'-*-cholesta- 

 dienol.^-^ It is unique in being one of the few sterols which have no 

 double bond in the Cs-Ce position. Additional information on the decom- 

 position products is given by Wieland and Benend.^^^ 



Other mycosterols which have been isolated from yeast include ascosterol 

 (C29H450H)^-* and several others named fecosterol, episterol, and neo- 

 sterol. The last is probably the so-called isoergosterol, and it contains 

 three unsaturated linkages. Still another yeast product which has been 

 prepared by Wieland and Joost^^^ is cryptosterol. It is possible that this 

 is another example of a triterpene, as it contains 30 carbons. 



c. Fatty Acids. The fatty acids which are combined with the higher 

 aliphatic alcohols or with the sterols in the waxes comprise many of those 

 which are frequently found as components of the triglycerides. Thus, 

 lauric (Ci-.), myristic (Ch), palmitic (Cie), and stearic (Cis) acids frequently 

 occur as components of the waxes. 



The larger proportion of acids present in the wax esters, however, are 

 those having longer chains than Cis. Carnaubic acid (C24), which is an 

 isomer of lignoceric acid, and myricinic acid (C30) are found in carnauba 

 wax; lacceric acid (C32) is a component of "stick-lac", geddic acid (C34) 

 occurs in ghedda wax, and carbocerotic acid (C27H54O2) is reported as a 

 component of Chinese insect wax. Cerotic acid, which occurs with mon- 

 tanic (C29) and melissic (C31) acids in beeswax, is a compound of disputed 

 composition. Cerotic acid is now generally believed to be a C26 saturated 

 straight-chain acid, although a number of authors, including Francis, 

 Piper, and Malkin,^* consider that the cerotic acids already described are 

 mixtures of C24, C26, and C28 acids. With the exception of lacceric acid, 

 all of the above long-chain fatty acids are classified as tso-acids, i.e., acids 

 having a forked chain. 



Unsaturated acids play a relatively insignificant role in the case of waxes, 

 in contrast to the important place they occupy in the case of the neutral 



3'' D. H. Cotfey, I. M. H.-ilhioii, and F. S. Spring, J. Chem. Soc, 1936, 738-741. 



3i« I. Smedley-MacLean, Biochem. J., 22, 22-26 (1928). 



319 H. Wieland, F. Rath, and \V. Benend, .4m/;., 048, 19-33 (1941). 



'20 F. Reindel and A. Weickmann, Ann., 475, 86-100 (1929). 



321 B. Heath-Brown, I. M. Heilbron, and E. R. H. Jone.s, J. Chem. Soc, 1940, 1482- 

 1489. 



322 H. Wieland and W. Benend, B>^r., 75, 1708-1715 (1942). 



323 H. Wieland, F. Rath, and H. Hesse, Ann., 548, 34-49 (1941). 

 32^ H. Wieland and E. Jocst, Ann., 546, 103-119 (1941). 



