This article covers the studies on phytoalexins activity of phenolic c
ompounds (cinnamic acids, flavonoids, isoflavonoids, deoxianthocyanins
, stilbenes, coumarins, chromones) against fungi and bacteria. The rel
ationship between hydrophilic-lipophilic balance activity is reported.
Finally some reports on the preparation of synthetic phytoalexins sha
ring structural similarities with the natural ones (stilbenes, epi-cat
echin derivatives), of commercial interest as pesticides, insecticides
and fungicides, are revised.