Transforms of o-coumaric acid(2-hydroxycinnamic acid), m-coumaric acid (3-hydroxycinnamic acid), p-coumaric acid (4-hydroxycinnamic acid), which, like other cinnamic acid derivatives and hydroxycinnamic acid derivatives, belong to the secondary plant substances. They consist of a C6-C3 skeleton and differ in the various substituents. substituents.
This group of polyphenols also includes caffeic acid (3,4-dihydroxycinnamic acid), chlorogenic acid (caffeic acid-quinic acid ester in Siberian spruce, hawthorn, artichokes, peach, red coneflower, potato, nettle), coumarin (o-coumaric acid lactone).