Preparation and purification of oligosaccharide from Radix Rehmanniae / 中草药

ABSTRACT

Objective To optimize the technique of isolating and extracting oligosaccharide from Radix Rehmanniae.Methods The optimum conditions for the water extracting technique of Radix Rehmanniae were studied by orthogonal test design.Then the water extract was isolated by macroporous resins and active charcoal successively,meanwhile the pattern of macroporous resins,the volume of the eluents,and the decolorizing methods of active charcoal were studied.And then the oligosaccharide was obtained after being purified by Sephadex gel column chromatography.The content of stachyose was determined by HPLC.Results The optimal preparation process was as follows 12 fold water,three times,0.5 h for each time.Then the water extract was isolated and purified by D-101 macroporous resins,0.1% active charcoal and Sephadex G15 column chromatography were successively used to obtain the oligosaccharide.The analysis of oligosaccharide indicated its main constituents are stachyose,rafinose,and manninotriose,and the content of stachyose is more than 60%.Conclusion This preparation technique of extracting oligosaccharide from Radix Rehmanniae is reasonable and feasible.And the yield of the oligosaccharide from Radix Rehmanniae achieves to 26%.