Rosmarinic Acid and Related Metabolites

Abstract

Rosmarinic acid, an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid, is a specialized plant metabolite that occurs in rather high quantities mainly in species of the subfamily Nepetoideae of the Lamiaceae and the Boraginaceae, but also occurs in separate taxa throughout the plant kingdom. Lamiaceae and Boraginaceae have been used to establish undifferentiated (callus, suspension) as well as transformed organ (hairy root) cultures. These often produce rosmarinic acid in higher quantities than intact plants. Other phenolic metabolites with a core structure containing rosmarinic acid coupled to another phenolic residue (e.g. 4-coumaric, caffeic or rosmarinic acid) can often be found as well. The most prominent conjugates are lithospermic acids, salvianolic acids and yunnaneic acids. The biotechnological production of rosmarinic acid and related phenolic acids has been intensively investigated because of their diverse biological activities. However, production processes using plant cell cultures at industrial scale have to date not been successfully established. This review gives an overview on the plant species and biotechnological cultivation systems which have been explored for the production of rosmarinic acid and related metabolites.