CHEMICAL PROPERTIES OF FATS AND OILS 291 



decrease in the stabilizing activity of hydroquinone occurs with the suc- 

 cessive addition of methyl groups. 



(c) Gossypol and Sesamol. Other antioxidants are present in vegetable 

 oils. These include gossypol in cottonseed oil and sesamol in sesame oil. 

 Mattill^*' and also Royce^""'^"^ demonstrated that gossypol, w hich may occur 

 in an amount as high as 1% in expeller oil, is an excellent antioxidant. In 

 fact, Roycc ascribes the stability of crude cottonseed oil, as compared with 

 the refined product, to this pigment. It has likewise proved effective in 

 the protection of lard from developing rancidity.*^' The formula for 

 gossypol given here^"- indicates the multiphenolic nature of the molecule to 

 which its stabilizing effect must be ascribed. 



CHO OH OH CHO 



II II 



HOC^ C ^C C^ C ^COH 



HOC. .'C <C C^^ C .COH 



^C^ V^ ^CH, H,C^ \^C/ \'^ 

 CH " " CH 



CHjCHj CH3CH3 



Gossypol 



Gossypol has been shown to be capable of protecting carotene from de- 

 struction in vitro by preformed fat peroxides.^"^ The protective action has 

 likewise been observed in vivo, where it was found that 1-milligram doses 

 either of gossj'pol or of dianilinogossypol were effective in preventing the 

 destruction of carotene fed with lard or with methyl linoleate.^"^ These 

 compounds had an activity only slightly inferior to that of s^nithetic a- 

 tocopherol. Cottonseed meal was found to be just as effective as wheat 

 germ in stabilizing carotene in ethyl oleate in vitro. 



Sesame oil has the property of protecting fats from developing rancidity 

 when mixed with them. The effective inhibitor has been showTi to be 

 sesamol,*-* which is closely related to sesamolin; this is believed to be a glu- 



CH^ — 



I /K 



0— C^ ^CH 



HC^ /COH 



H 

 Sesamol 



wo H. D. Royce, Oil & Soap, 10, 123-125 (1933). 



wi H. D. Royce and F. A. Lindsey, Jr., Ind. Eng. Chem., 25, 1047-1050 (1933). 

 "* R. Adams, R. C. Morris, T. A. Geissmaii, D. J. Butterbaugh, and E. C. Kirkpatrick, 

 J. Am. Chem. Soc, 60, 2193-2204 (1938). 



«>» E. L. Hove and Z. Hove, J. Biol. Chem., 156, 611-621 (1944)* 

 »« E. L. Hove, J. Biol Chem.^ 156, 633-642 (1944). 



