Phenylamides in plants

Phenylamides, secondary metabolites, conjugates of aliphatic polyamines or arylmonoamines and hydroxycinnamic acids, combining the properties of both parent compounds, are a subject of increasing interest, as follows from their ubiquitous distribution and multiplicity of functions. In this paper the occurrence, distribution, localization, metabolism, as well as chemical structure and properties of phenylamides underlying their physiological functions are briefly reviewed, with an emphasis on their involvement in the developmental and stress-defense phenomena of plants. Basic knowledge on phenylamides is supplemented with recent data pointing to the structural similarity of plant phenylamides with those found in insect toxins. This finding challenges the view of phenylamides as plant-specific molecules and suggests their role as a common defense tool in various organisms.