Formation of coenzyme a esters of cinnamic acids with an enzyme preparation from cell suspension cultures of parsley

The formation of coenzyme A thiol esters of cinnamic, p-coumaric, p-methoxy cinnamic, and ferulic acids was catalyzed by enzyme preparations from cell suspension cultures of leaf petioles from parsley (Petroselinum hortense Hoffm.). Of these acids, p-coumaric acid served as the most efficient substrate. Enzyme activity is markedly increased upon illumination with white light in a manner very similar to that in which the activities of a number of enzymes involved in flavone biosynthesis are stimulated by light. This strongly suggests that the formation of p-coumaroyl coenzyme A is part of this biosynthetic pathway.