Selective Inhibition of SV40-transformed Cell Growth by Diketopiperazines

Abstract

Two diketopiperazines have been isolated from the culture broth of a soil Actinomycetales, Streptomyces sp. strain ML1532. They were cyclo(L-Val-L-Pro) and cyclo(L-Tyr-L-Pro). The selective cytotoxicity of cyclo(L-Tyr-L-Pro) was slightly higher than that of cyclo(L-Val-L-Pro) against SV40-transformed cells.