702 



XI. VITAMINS E (tocopherols) 



CH, 



HOC C 

 H3CC C 



c 

 CH3 



H2 

 c 



CH2 



C— (CHo )3— CH— ( CH2)3— CH— ( CH2 )3— CH— CH3 

 O CH3 CH3 CH3 CH3 



a-Tocopherol 



CH3 



^ 



HOC 



V 



H2 

 c 



CH2 



H3C 



c 



CHo 



C HOC— C16H3 

 OH CH3 



a-Tocopherylhydroquinone 

 First Steps in the Catabolism of a-Tocopherol 



Although these oxidation products probably do not function as com- 

 ponents of an oxidation -reduction system, as was formerly believed, they 

 still are of importance, inasmuch as they have been sho\vn by Mackenzie 

 and Mackenzie^-^ to be active as antidystrophic agents. 



Simon, Gross, and Milhorat^°^ found another major intermediate in the 

 urine and feces of rabbits given labeled tocopherol, and in the urine of 

 human subjects ingesting large amounts of a-tocopherol.^"'' This degrada- 

 tion product appears to be a derivative of a-tocopherol in which the side 



'>» J. B. Mackenzie and C. G. Mackenzie, Proc. Soc. Exptl. Biol. Med., 84, 388-392 

 (1953). 



