N-(3-methyl-2(S)-(cysteinylamino)but-1-yl)phenylalanyl-methionine 、 N-[2(S)-(2(R)-t-butoxycarbonylamino-3-triphenylmethylmercaptopropylamino)-3(S)-methylpentyl]phenylalanyl-methionine 生成 N-[2(S)-(2(R)-amino-3-mercaptopropylamino)-3(S)-methyl]pentyl-phenylalanyl-methionine