Rosmarinic Acid (RA)

Rosmarinic acid is a caffeic acid ester found in a variety of plants. It has antioxidant or medicinal properties. The biosyntheses of caffeoylshikimate, chlorogenic acid and rosmarinic acid use 4-coumaroyl-CoA from the general phenylpropanoid pathway as hydroxycinnamoyl donor. The hydroxycinnamoyl acceptor substrate comes from the shikimate pathway: shikimic acid, quinic acid and hydroxyphenyllactic acid derived from l-tyrosine. Thus, chemically, rosmarinic acid is an ester of caffeic acid with 3,4-dihydroxyphenyl lactic acid, but biologically, it is formed from 4-coumaroyl-4'-hydroxyphenyllactate. Rosmarinate synthase is an enzyme that uses caffeoyl-CoA and 3-(3,4-dihydroxyphenyl)lactate to produce CoA and rosmarinate. Hydroxyphenylpyruvate reductase is also an enzyme involved in this biosynthesis. Rosmarinic acid and a rosmarinic acid 3′-O-β-D-glucoside can be found in Anthoceros agrestis, a hornwort (Anthocerotophyta).