Targeted preparation of six rare ginsenosides using two β-glucosidases from Bifidobacterium adolescentis

In this study, six rare protopanaxadiol (PPD)-type ginsenosides, namely, F2, CK, C-Mc1, C-Mc, CO, and CY, were prepared using enzymatic hydrolysis. Firstly, major (PPD)-type ginsenosides, including Rb1, Rb2, Rc, and Rd, were biotransformed by employing single and combined β-glucosidases BaBgl1A and BaBgl3A. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analyses revealed that ginsenosides F2, CO, and C-Mc1 could be produced by BaBgl1A, while rare ginsenosides CK, CY, and C-Mc could be produced by the combined use of BaBgl1A and BaBgl3A. Furthermore, optimal preparation conditions for these rare ginsenosides were elucidated, with yields exceeding 76.34%. Additionally, large quantities of rare ginsenosides were prepared to determine their structures. Characteristic absorption peaks in 13C-NMR spectra and ion peaks in MALDI-TOF-MS suggested that the six high-purity rare ginsenosides (i.e., F2, CO and C-Mc1, CK, CY, and C-Mc) could be produced at high-efficiency. The findings of this study offer insights into novel enzymolysis methods for the targeted preparation of rare PPD-type ginsenosides, thus widening the range of raw materials that could be directed to in-depth biological activity research.