Selection of high-yield hairy root clone of ginseng and separation and purification of ginsenoside Rb1 from ginseng hairy root

Hairy roots of ginseng were directly inoculated from the root explants of two-year-old ginseng by Agrobacterium rhizogene A4. The specific growth rate and the ginsenoside content of sixteen kinds of hairy roots were measured, from which three high-yielding clones were selected. The highest-yielding clone was R9923 whose biomass increased by 28.8 times after four weeks culturing. The growth of the hairy root and the development of ginsenoside of clone R9923 were investigated and it was found that the ginsenoside content increases with the biomass of the hairy root. The contents of monomer ginsenoside Rg1, Re and Rb1 in clone R9923 were determined by HPLC method. The total content of ginsenoside in the hairy root after four weeks culturing came up to 15.2 mg/g, in which 68.3% was Rb1. The content of Rb1 in the hairy root was 2.3 times of that of three-year-old ginseng. The ginsenoside Rb1 was separated and purified from the hairy root by silica gel column chromatography, in which the optimal solvent ratio of chloroform to methanol was 7.5:2.5, the purity of Rb1 was 89.95% and the yield was 72.7%.