Chemistry of renieramycins. Part 5. Structure elucidation of renieramycin-type derivatives O, Q, R, and S from thai marine sponge Xestospongia species pretreated with potassium cyanide.

Four minor renieramycin-type derivatives, including renieramycins O (1o) and Q-S (1q-s), were isolated from the sponge Xestospongia sp. pretreated with potassium cyanide. Their structures were elucidated by comparison of spectral data with those of recently reported renieramycins M (1m) and N (1n). The results of transformation and cytotoxicity measurements are also described.