TRIGLYCERIDES AND FATTY ACIDS 



I If) 



required or effective for the lipoxidase preparation of Smith and Sumner,-^- 

 nor has it been found to be necessary to activate crystaihne hpoxidase.'*'* 



(/) The Mechanism of Action of Ldpoxidase. It has been suggested that 

 the course of oxidation catalyzed by hpoxidase is similar to that occurring 

 in the autoxidation of fats;-^^-^^"* hydroperoxides are formed, which are 

 largely conjugated. Holman^^^ and Bergstrom and Holman^^^ later showed 

 that, with a low substrate concentration, and at 0°C., linoleic acid is oxi- 

 dized to yield totally conjugated peroxides. When the temperature is 

 increased, side reactions or subsequent oxidation or decomposition of the 

 peroxides occurs. The postulated pathway of oxidation is given below: 



13 12 11 10 9 

 — CH2CH:CHCH2CH:CHCH— (I) 



-H- 



— CH2CH:CHCHCH:CH-CH2 



(11) 



(III) i/ \ (IV) 



-CH2CH:CHCH:CHCHCH2— . — CH2 CHCH:CHCH:CHCH2 



(V)i 



+ O2 



+O2 



(VI) 



-CH2CH:CHCH:CHCHCH2— — CH2■CH•CH:CH•CH:CH•CH2- 

 00 • ( )( ) • 



(VII) i 



+ H- 



+ H- 



(VIII) 



— CH2CH:CHCH:CHCHCH2— — CH2•CH•CH:CH•CH:CH•CH2— 

 OOH OOH 



The Oxidation of Linoleic Acid with Lipoxidase as Proposed by Bergstrom and Hol- 



mani"'255 



The oxidation of linoleic acid proceeds in the form of a chain reaction, 

 as a result of the transfer of a hydrogen from the methylene group on Cn of 



232 G. N. Smith and J. B. Sumner, Arch. Biochem., 19, 89-94 (1948). 

 "3 S. Bergstrom, Arkiv. Kemi, Mineral., GeoL, SI A, No. 15, 1-8 (1945). 

 "4 R. T. Hohnan, Arch. Biochem., 10, 519-529 (1946). 

 "5 S. Bergstrom and R. T. Holman, Nature, 161, 55 (1948). 



