A new malyngamide from the marine cyanobacterium Moorea producens.

A new malyngamide (1) was isolated along with seven known compounds (2-8) from the marine cyanobacterium Moorea producens collected in Hawaii. Compound 1 represented the first reported malyngamide with a hydroxy moiety at C-7 of the characteristic fatty acid portion of the compound. Compound 1 showed cytotoxicity against L1210 cell line at an IC50 value of 2.9 mM and lethal toxicity against the shrimp Palaemon paucidens at a LD100 value of 33.3 mg/kg. The bioactivity of compound 1 was approximately 10-100 times weaker than those of isomalyngamides A and B (3, 4). These results indicated that the methoxy group at C-7 of the fatty acid section confers a degree of bioactivity in malyngamides.