Isolation of p-hydroxycinnamaldehyde as an antibacterial substance from the saw fly, Acantholyda parki, S.

We purified an antibacterial substance from larvae of the saw fly, Acanthol yda parki S,, and identified its molecular structure as p-hydroxycinnamalde hyde. We then synthesized it by reduction of p-hydroxycinnamic acid. The an tibacterial activity of the synthetic p-hydroxycinnamaldehyde was equal to that of the authentic substance. This molecule was found to have a broad an tibacterial spectrum against not only Gram-negative, but also Gram-positive bacteria. Furthermore, it showed antifungal activity against Candida albic ans. We suggest that this substance may play a role in the defense system o f this insect. This is the first report of p-hydroscinnamaldehyde of animal origin. (C) 1999 Federation of European Biochemical Societies.