Onnamide F: A new nematocide from a southern Australian marine sponge, Trachycladus laevispirulifer

A southern Australian marine sponge, Trachycladus laevispirulifer, has yiel ded a potent new nematocide with antifungal activity which has been identif ied as onnamide F (1). The structure for 1 was assigned by detailed spectro scopic analysis and chemical conversion to the methyl ester 2. Onnamide F c ontains a common structural motif previously described in a number of natur al products exhibiting interesting pharmacological activities, including th e insect chemical defense agent pederin (3), and the sponge metabolites the onnamides, mycalamides, and theopederins.