Zur Autoxydation der ungesättigten Fettsäuren. II. Die Wirkung der Carotinoide.

Abstract

The carotinoids in the absence of hematin act as positive catalyzers in the autoxidation of unsaturated free fatty acids, but they do not affect the tri-glycerides. Vitamin A and carotin do not differ from other lipochromes in this respect. The relative solubilities of the reactive series of fatty acids may be the basis for their easy autoxidizability in the presence of carotin. In the presence of hematin, lipochromes cause a definite increase in autoxidation of neutral oils (not of the free fatty acids). This may be due to the formation of a hematin-carotin complex. In pyridine, but not in other solvents, the lipochromes decrease the autoxidation of unsaturated fats and fatty acids. Explanation of this is sought on the basis of the theory of chain structure. In dimethyl-anilin, the presence of hematin results in an unusually rapid and extensive autoxidation of the lipochromes as well as of the unsaturated fatty acids. The autoxidizing activity of the individual carotinoids dissolved in xylol in the presence or absence of hematin was investigated. Their greatest effectiveness as catalyzers was established by comparison with the reaction velocity of the unsaturated fattv acids.