KEENAMIDE-A, A BIOACTIVE CYCLIC PEPTIDE FROM THE MARINE MOLLUSK PLEUROBRANCHUS-FORSKALII

Keenamide A (1), a new cytotoxic cyclic hexapeptide, was isolated from the notaspidean mollusk Pleurobranchus forskalii. Its structure was d etermined by NMR spectral data interpretation and chiral amino acid an alysis. Keenamide A (1) exhibited significant activity against the P-3 88, A-549, MEL-20, and HT-29 tumor cell lines, but was inactive when e valuated against the D6 and W2 Plasmodium falciparum malarial clones.