Isolation and structural elucidation of the crellastatins I-M: cytotoxic bissteroid derivatives from the vanuatu marine sponge Crella sp

Continued investigation of cytotoxic exts. of the marine sponge Crella sp. has resulted in the discovery of crellastatins I-M (e.g. I, crellastatin I). Their structures were detd. by interpretation of their NMR spectroscopic and FABMS data. These new bis-steroid derivs. exhibited cytotoxic activity against NSCLC cell lines with IC50 values in the range of 1-8 .mu.g/m