Novel antifungal diketopiperazine from marine fungus

Marine fungi producing antifungal compounds were screened against Pyricularia oryzae (P oryzae), and a metabolite of marine fungus M-3 isolated from laver (Porphyra yezoensis),showed potent activity. Novel diketopiperazine (1) was isolated from the culture extracts, and its structure was elucidated by spectroscopic methods. The MIC of 1 against P. oryzae was 0.36 muM.