Didmolamide A and B, two new cyclic hexapeptides from the marine ascidian Didemnum molle

Two novel cyclic hexapeptides, didmolamides A and B, were isolated from the compound ascidian Didemnum molle collected in Madagascar. The structure of the two peptides was elucidated by interpretation of MS, COSY, HMQC, and HMBC data. The absolute configuration of all amino acids was determined to be l using Marfey's method for HPLC.