Applied Microbiology and Biotechnology, Vol.98, No.17, 7399-7408, 2014
Enzymatic synthesis of L-norephedrine by coupling recombinant pyruvate decarboxylase and omega-transaminase
l-Norephedrine, a natural plant alkaloid, possesses similar activity as ephedrine and can be used as a vicinal amino alcohol for the asymmetric synthesis of a variety of optically pure compounds, including pharmaceuticals, fine chemicals, and agrochemicals. Because of the existence of two asymmetric centers, efficient synthesis of l-norephedrine has been challenging. In the present study, an R-selective pyruvate decarboxylase from Saccharomyces cerevisiae and an S-selective omega-transaminase from Vibrio fluvialis JS17 were coupled to develop a sequential process for the stereoselective biosynthesis of l-norephedrine. After systematic optimization of the reaction conditions, a green, economic, and practical biocatalytic method to prepare l-norephedrine was established to achieve de and ee values of greater than 99.5 % and a molar yield over 60 %. The present coupling approach can facilitate the development of sequential reactions by various biocatalysts.
Keywords:L-Norephedrine;L-Phenylacetylcarbinol;Biosynthesis;Pyruvate decarboxylase;omega-Transaminase