Linoleic Acid Oxidation Catalysed by Various Amino Acids and Cupric Ions in Non‐Aqueous Media

Abstract

AbstractThe effect of amino acids under the present investigation on linoleic acid oxidation in non‐aqueous media has shown feature of an autocatalytic chain reaction and possessed minor antioxidant behaviour except cysteine. The antioxidant effect might be attributed to the absence of protonated amino nitrogen. Linoleic acid alone had an induction period of 15 hr and on the addition of various α‐amino acids, the systems had an induction period ranged from 16–19 hr. This increase did not exhibit any specific function for the studied amino acids. Cysteine exceptionally possessed pro‐oxidant effect and that was due to the role of HS‐group. The addition of copper at concentrations of 10−5 M and 10−3 M to the model systems composed of linoleic acid and various α‐amino acids in non‐aqueous media have shown to exhibit minor and highly pro‐oxidant effects respectively. The pro‐oxidant effect of these amino acids in the presence of copper might be due to amino acids‐copper complexes.