32 



II. CHEMISTRY OF FATTY ACIDS AND GLYCEROL 



"WTien a-licanic acid (m.p. 74-75°C.) is subjected to traces of iodine or 

 sulfur or exposed to sunlight,^ it is converted to /3-licanic acid^"~^" which 

 melts at a higher temperature (m.p. 96.5°C.). Licanic acid also readily 

 undergoes polymerization because of its conjugate double bond system; 

 under such conditions, it forms films resistant to both water and 

 alkali, which resemble those produced by elaeostearic acid. 



Table 5 

 Branched-Chain Acids Which Have Been Isolated from Biological Material 



" M. E. Chevreul, Recherches rhimiques sur les corps gras d'oriqine animale, Levrault, 

 Paris, 1823, p. 115. Cited in Beilstein, Handbuch org. chem., 135, 4th ed., Yo]. II, 1920, 

 p. 309; also K. S. Marklev," p. 38. 



'• R. J. Anderson and ]•:. Chargaff, ./. Biol. Chem., 86, 77-88 (1929). 



' M. A. Spielman and R. J. Anderson, ./. Biol. Chem., 112, 759-767 (1936). 



^ L. G. Ginger and R. J. Anderson, ,/. Biol. Chem., 156, 443-451 (1944). 



•^ F. H. Stodola, A. Lesuk, and R. J. Anderson, ./. Biol. Chem., 126, 505-513 (1938). 



f L. G. Ginger and R. J. Anderson, J. Biol. Chem., 157, 203-211 (1945). 



" S. F. Velick and R. J. Anderson, ./. Biol. Chem., 152, 523-531 (1944). 



The chief source of licanic acid is oiticica oil from the Licania rigida 

 (oiticica),'-" where it makes up 75-80% of the fatty acid. Mexican oiti- 

 cica oil from the Licania orborea^-^-^ ("cacahuananche") is also a good 

 source, as is po-yoak oiP'-^ obtained from Parinarium sherbroense* from 

 Sierra Leone. In the latter case, 45-50% of the total fatty acid consists 

 of licanic acid and about 30% of elaeostearic acid.* 



(7) Miscellaneous Siibstihded Acids 



Although practically all of the fatty acids found in nature are straight- 

 chain compounds, a few cases are known in which branched-chain acids 



126 R. S. Morrell and W. R. Davis, /. Chem. Soc., 1936, 1481-1484. 



127 R. S. Morrell and W. R. Davis, J. Oil Colour Chem. Assoc., 19, 359-362 (1936). 



128 H. A. Gardner, Nat. Paint Varnish Lacquer Assoc, Giro. No. 654, 28-34 (1943). 



129 A. Steger and J. Van Loon, Rec. trav. chim., 57, 620-628 (1938). 



