摘要：Antioxidative and synergistic activities of 14 cysteine derivatives and 10 dipeptide derivatives with the sequences Cys (R)-Ser and Ser-Cys (R) were investigated, using an autoxidative system of linoleic acid, and the following results were obtained : 1) None of the tested compounds showed any marked antioxidative activity against autoxidation of linoleic acid. 2) In general, S-alkylcysteines were synergistically effective with both dl-α-tocopherol and dibutylhydroxytoluene (BHT). On the other hand, cysteine markedly increased POV of the system in the presence of BHT, while it showed synergistic activity toward α-tocopherol. 3) Blocking of the amino group of cysteine and S-alkylcysteines caused the loss of their synergistic activities, while blocking of the carboxyl group gave products with proxidative activity in the presence of antioxidants. 4) Both Cys (Bzl)-Ser and Ser-Cys (Bzl) showed synergistic effect nearly equal to their constituent amino acids. In analogy with S-alkylcysteins, blocking of the terminal groups, especially the carboxyl group, caused appreciable loss in the synergistic activities of the dipeptides, and a potent proxidative activity was observed with some blocked peptides including Ser-Cys (Bzl)-OBzl, BOC-Ser-Cys (Bzl)-OBzl, and Z-Cys (Bzl)-Ser-OMe. These results suggested that the synergistic action of cysteine derivatives and cysteine-containing peptides might be caused by cooperative action of blocked SH group and free NH2 and COOH groups.
