Isolation and structure of the human cancer cell growth inhibitory cyclic decapeptides phakellistatins 7, 8 and 91,2

Phakellistatins 7–9 respresent the first cancer cell growth inhibitory (P388 ED50 3.0, 2.9 and 4.1 μg/mL respectively) cyclic decapeptides. Each was isolated from the Federated States of Micronesia (Chuuk) marine sponge Phakellia costata. Abstract The Federated States of Micronesia (Chuuk) marine sponge Phakellia costata has been found to contain (10−5 and 10−6% yields) three cancer cell line active (P388 ED50 3.0, 2.9 and 4.1 μg/mL respectively) cyclic decapeptides named