Abstract
Antioxidative effects of metabolites of tryptophan (Try) on the autoxidation of oil have been studied little. Present paper deals with the antioxidative activities of Try, kynurenine (Kyn), kynurenic acid (Ky. A), xanthorenic acid (Xa. A), anthranilic acid (An. A), 3 or 5-OH-anthranilic acid (3 or 5-OH-An. A), 5-OH-tryptamine (5-OH-Try. Am), tryptamine hydrochloride (Try. Am-HCl), β-nicotinamide adenine dinucleotide (NAD) and alanine (Ala) using A.O.M., oven test, weighing method test and DPPH method (1, 1-diphenyl-2-picrilhydrozil).
The results obtained were as follows;
1) 3-OH-An. A was the most effective and followed by 5-OH-An. A, Ala, NAD>An. A, Try, Ky. A, Xa. A in decreasing order.
2) 5-OH-An. A showed great antioxidant activity at the concentration of 0.003% by A.O.M. test.
3) Mixture of 3-OH-An. A, 5-OH-An. A, Ala and Ala-NAD was more effective than each of them.
4) The mixture of tocopherol and Try or 5-OH-An. A had a greater antioxidative activity than tocopherol or 5-OH-An. A.
5) When oil was heated for 10hr, antioxidative activity of 5-OH-An. A was decreased, but tocopherol still kept the activity.
