The Isolation And Structure Elucidation Of Triterpenoid Saponins From Radix Achyranthis Bidentatae

Radix Achyranthis Bidentatae is a Chinese traditional tonic herb, which has various biological functions , and plays an important role in clinic , such as anti-fertility, anticancer, antibacterial, immune adjustment and anti-inflammatory activity. Radix Achyranthis bidentatae has many constituents, such as polysaccharide, triterpenoid saponins, steroids. Chemical studies of the triterpenoid saponins were carried out in this paper. In the experiment, we firstly obtained achyranthes bidentata saponins(ABS) from Radix Achyranthis bidentatae by ethanol extraction and resin column elution. The crude saponins were first methylated with diazomethane, and then isolated and purified through silica gel column chromatography. Three triterpenoid saponins were obtained and their structures were identified through analyzing physical and chemical constants and spectroscopic data as I 1′′′, 1′′, 6′–O–trimethyl–3–O–(3′′–carboxymethoxy-3–oxopyruvic acid 3′–acetal –2′′–methoxy –4′–ketal )-β-D-glucuronopyranosyl oleanolic acid-28–O–β–D–glucopyranosyl ester, II 6′–O –methyl –3-O –β–D –glucuronopyranosyl oleanolic acid -28–O–β–D–glucopyranosyl ester, III 6′–O–methyl –3–O –β–D –glucopyranosyl (1→2)–β–D –glucuronopyranosyl oleanolic acid-28–O–β–D–gluc-opyranosyl ester, respectively.