Notoamide O, a Structurally Unprecedented Prenylated Indole Alkaloid, and Notoamides P-R from a Marine-Derived Fungus, Aspergillus sp.

Notoamides O-R were isolated from a marine-derived Aspergillus sp. Notoamide O possesses a novel hemiacetal/hemiaminal ether functionality hitherto unknown among this family of prenylated indole alkaloids. The structure represents an unusual branch point for the oxidative modification of other members in the family of prenylated indole alkaloids in the biogenetic pathway.