Cyclic dipeptides from marine-derived microorganisms and their antitumor activity

摘要

In the course of our studies on new anticancer agents from microbial resources, we have undertaken a program for screening marine-derived microorganisms by using tsFT210 cells. By the screening of more than three thousands of microbial strains, we found that the fermentation products of some marine-derived microbes, actinomycete strains, 9002, B2202, 329 and H2003, and fungal strains, 3200 and H1-04, significantly inhibited the proliferation of tsFT210 cells. Preliminary examinations indicated that the bioactive components produced by these strains are extracted by the EtOAc-extraction. From the EtOAc extracts obtained through the fermentation of the strains, we have isolated more than ten of compounds and eleven of them are identified as 2,5-diketopiperazine derivatives belonging to the cyclic dipeptides (1-11 in Fig. 1). Effects of 1-11 on the tsFT210 cells were also evaluated.