Studies On The Chemical Constituents And The Separation Technology Of Minor Ginsenosides From The Flower Buds Of Panax Ginseng C.A.Meyer

In this study,the chemical constituents in the flower buds of Panax ginseng were comprehensively studied,and we also developed the separation technology for the isolation and purification of minor ginsenosides.The main contents are as follows:1.The flower buds of Panax ginseng was extracted by refluxing with methanol.The extract was concentrated and prepared into suspension,then extracted with hexane and ethyl acetate.The extract was concentrated to obtain the fraction of hexane,ethyl acetate and water.This study took the water fraction as the research object,by combining different chromatographic separation and purification method such as macroporo us resin column,MCI column,silica gel column and semi preparative HPLC,to identify and obtain 56 pure compounds finally by NMR,MS and IR.Among them,seven of which are new compounds;one is new natural compound;and the 26 known compounds were isolated from ginseng buds for the first time.This study further enriched the chemical resource pool of ginsenoside compounds.2.We developed a method for the separation of ginsenoside RK1,ginsenoside Rg₅,ginsenoside M1 and a new pair of isomer ginsenosides 20?R?–methoxy-ginsenoside Rg₃,20?S?–methoxy-ginsenoside Rg₃ by C18 solid phase extraction and semi-preparative HPLC.The chromatographic conditions of HPLC were optimized,and the quantitative analysis was carried out to determine the contents of ginsenoside RK1,ginsenoside Rg₅,ginsenoside M1,20?R?-methoxy-ginsenoside Rg3,20?S?–methoxy-ginsenoside Rg₃ in ginseng flower buds,and this study will provide a theoretical basis for the totally quality control of ginseng flower buds.3.We developed a separation technology by ultrasound-assisted extraction through the optimization of extraction solvents,solvent to solid ratio,temperature,ultrasound power and extraction time to obtain an optimum conditions for the extraction of 11 minor ginsenosides including vinaginsenoside R₈?vinaginsenoside R₄?3-O-?-D-glucopyra nosyl-20-O-?-D-glucopyranoside-dammar-5?6?,24-diene-3?,7?,12?,20S-tetraol?notoginseno side E? ginsenoside ??ginsenoside F₅?20?S?-ginsenoside Rh₁?20?R?-ginsenoside Rh₁?ginsenoside Rc?ginsenoside Rb₂ and ginsenoside F₁.This study will provide a theoretical foundation for the further development and application of saponins in ginseng flower buds.