ANTINEOPLASTIC AGENTS SERIES .279. ISOLATION AND STRUCTURE OF AXINASTATIN-4 FROM THE WESTERN INDIAN-OCEAN MARINE SPONGE AXINELLA-CF CARTERI

The Republic of The Comoros marine sponge Axinella cf. carteri has bee n found to contain a cell growth inhibitory (P388 lymphocytic leukemia cell line ED50 0.057 mug/ml, and comparable activity against a series of human cancer cell lines) cyclo-heptapeptide named axinastatin 4 (3 ). The new peptide was obtained in 1.0 x 10(-6)% yield (6.1 mg) from 6 00 kg (wet wt) of the sponge. The structure of axinastatin 4 was deduc ed as cyclo-(Pro-Leu-Thr-Pro-Leu-Trp-Val) by a combination of high fie ld (400 and 500 Mhz) 2D nmr (H-1-H-1, H-1-C-13, HMBC and NOE) and high resolution mass spectral (principally by ms/ms) measurements and subs equent interpretations.