Two New Enzymes of Rosmarinic Acid Biosynthesis from Cell Cultures of Coleus blumei: Hydroxyphenylpyruvate Reductase and Rosmarinic Acid Synthase

Abstract

Rosmarinic acid biosynthesis can be stimulated in cell cultures of Coleus blumei by culturing the cells in medium with 4% sucrose. In enzyme extracts of these cells two new enzymes of rosmarinic acid biosynthesis were discovered. Hydroxyphenylpyruvate reductase reduces 4-hydroxyphenylpyruvate and 3,4-dihydroxyphenylpyruvate to 4-hydroxyphenyllactate and 3,4-dihydroxyphenyllactate, respectively, using NADH. Rosmarinic acid synthase transfers the caffeoyl moiety of caffeoyl-CoA to the non-phenolic OH-group of 3,4-dihydroxyphenyllactic acid, in course of which rosmarinic acid is formed.