Biotransformation of ginsenoside Rb1 for ginsenoside Rd preparation by <i>Lysinibacillus massiliensis</i> No. 24

Abstract

Bacterium <em>Lysinibacillus massiliensis </em>No. 24 was tested for its ability to transform the major ginsenosides Rb1. The transformation product was identified by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC), and its structure was assigned by ¹³C-NMR. The bacterium was found to specifically transform major ginsenoside Rb1 and ginsenoside Rd was the sole product. The optimal conditions for transforming Rb1 by <em>L. massiliensis </em>No. 24 were determined to be: substrate concentration, 3 mg/mL; temperature, 34&deg;C; pH 10; the time of substrate addition, 48 h; cell concentration, 0.30&times;10⁹ cells/mL; and biotransformation period, 3 d. Under the optimum conditions, the maximum yield of ginsenoside Rd reached 97%. Further, a preparative scale transformation with <em>L. massiliensis</em> No. 24 was performed with 150 mg Rb1 to give a yield of 79%. This bacterium would be potentially applied in the preparation of Rd.