ABSTRACT
I. INTRODUCTION The hydroxycinnamic acids are phenylpropanoid plant metabolites, chemically and biologically related, that are commonly found in plant-derived foodstuff (1). Among them, caffeic acid, its quinic ester derivative, chlorogenic acid, as well as its precursor, p-coumaric acid, are the phenolic acids most widely distributed in plant tissues. In addition to other functions, they take part in the biosynthesis of the more complex and more studied class of phenolic compounds, the flavonoids (2,3). Evidence concerning the antioxidant and anticarcinogenic properties of these phenolic acids originates from epidemiological studies (4-6), that inversely associate fruit and vegetable intake with the incidence of coronary heart disease and cancer, and are supported by biological and biochemical data.
