Kahalalide F analogues from the mucous secretion of Indian sacoglossan mollusc Elysia ornata

Bioassay-guided fractionation of the CHCl3-MeOH extract of Elysia ornata mucus showing antifungal activity led us to isolate kahalalide F (KF) along with two unprecedented related peptides. The structures of kahalalide Z1 (1) and kahalalide Z2 (2), were established by combination of NMR spectroscopic and mass spectrometry data, also including Marfey aminoacid analysis. Compounds 1 and 2 displayed significant antimicrobial properties against several fungal pathogens infesting economically important plants, food and fish, and were also found to inhibit the in vitro growth of a series of cancer cell lines in a comparable fashion with KF.