Synthesis and antitumor activity of cyclodepsipeptide zygosporamide and its analogues

The synthesis and structure–activity relationships of zygosporamide, a known potent and selective cytotoxic natural product against SF-268 and RXF 393 cell lines, are described. The potencies of the synthetic zygosporamide are similar to those reported for the natural product toward all cancer cell lines examined with the exception of SF-268, the underlying cause of which remains to be elucidated.