采用多肽固相合成法合成的胸腺生成素II和胸腺素的活性片段TP-5, Thy(1[Lys23]用2,2,5,5-四甲基-3-烯-4-羟基-1-氧吡咯氮氧自由基标记的自旋标记物在体外黄嘌呤氧化酶体系中可清除超氧阴离子，保护对红细胞的损伤。小鼠腹腔连续注射10 (g(kg(d-1 TP-5, Thy(1[Lys23]的活性片段及它们的自旋标记衍生物10天后，其肝、脑、胸腺中脂质过氧化物含量降低。提示此两种多肽及其自旋标记衍生物具有抗氧化活性。 Thymosin II and thymosin active fragments TP-5 and Thy (1 [Lys23] synthesized by peptide solid phase synthesis were treated with 2,2,5,5-tetramethyl-3-en-4- - pyrrole nitroxide-labeled spin label can eliminate superoxide anion and protect the erythrocytes from xanthine oxidase system in vitro.Mice were injected intraperitoneally with 10 (g (kg) d-1 TP-5 , Thy (1 [Lys23] active fragments and their spin-labeled derivatives 10 days, the liver, brain, thymus lipid peroxide content decreased.It is suggested that these two polypeptides and their spin-labeled derivatives have anti Oxidative activity.