| Ginsenosides are the major active compounds of ginseng and widely distributed in the roots,stems,leaves,flowers and fruits of plants.Ginsenosides have a variety of pharmacological activities such as anti-inflammatory,anti-tumor,anti-fatigue,and immune enhancement.The sugar chains are closely related to its pharmacological activities.The changing of sugar chains can change the pharmacological activities of ginsenosides.Therefore,the preparation of a series of ginsenosides with different sugar chainscan elucidate the structure-activity relationship of ginsenosides and provide tremendous compounds resources for drug development.To date,more than 200 natural ginsenosides have been isolated and identified,however,most of them are still difficult to obtain in large quantities,which limits their clinical application and industrial production.Among them,ginsenoside Rb2,Rb3 and Rc are difficult to separate directly from total ginsenosides due to their similar polarities.In this paper,ginsenosides which are similar to the target ginsenosides are converted into rare ginsenosidesby various specific glycosidases,then ginsenoside Rb2,Rb3 and Rc are prepared by silica gel chromatography.A series of rare ginsenosides were prepared by glycosidase from Rb2,Rb3 and Rc,respectively.The main results of this paper are as follows:Glycosidases Ccbgl3 B,Bgp2,CS-abf and Bglpc28 are prepared respectly,which can hydrolyze the C-20 outer glucose,pyranose arabinose,furan arabinose,and C-20 inner glucose.The Rb2-rich total ginsenosides are converted to Rb2 and Rg3 by Ccbgl3 B,CS-abf and Bglpc28 and ginsenoside Rb2 can obtained by Silica gel column chromatography.The purity and yield of Rb2 are 93% and 40%.The Rb3-rich total ginsenosides are converted to Rb3 and Rg3 by Ccbgl3 B,CS-abf,Bgp2 and Bglpc28 and ginsenoside Rb3 can obtained by Silica gel column chromatography.The purity and yield of Rb3 are 91.5% and 47.1%.The Rc-rich total ginsenosides are converted to Rc and Rg3 by Ccbgl3 B,Bgp2,and Bglpc28 and ginsenoside Rc can obtained by Silica gel column chromatography.The purity and yield of Rc are 92.5% and 49.5%.Glycosidase CcBgl1 A which can hydrolyze the C-3 outer glucose is prepared.Ginsenoside Rb2,Rb3 and Rc are converted to rare ginsenosides C-O,C-Mx1 and C-Mc1 by CcBgl1 A,respectively.The purity of the three products is 94.5%,97.5% and 98% by silica gel column chromatography.The yield is 31%,30.5% and 30%,respectively.Ginsenosides Rb2,Rb3 and Rc are converted to ginsenoside C-Y,C-Mx and C-Mc by CcBgl1 A and Bglpc28,respectively.The purity of the three products is 95.2%,95% and 97.3% by silica gel column chromatography.The yield is 20%,22% and 19.5%,respectively. |
