p. 4283 - 4285
(1982)(S)-4-{2-[(R)-2-(2-Acetylamino-acetylamino)-3-(4-methyl-benzylsulfanyl)-propionylamino]-acetylamino}-4-[(S)-3-carbamoyl-1-((S)-1-carboxy-2-methylcarbamoyl-ethylcarbamoyl)-propylcarbamoyl]-butyric acid benzyl ester
[(R)-2-(2-Acetylamino-acetylamino)-3-(4-methyl-benzylsulfanyl)-propionylamino]-acetic acid