Change of oligosaccharide and catalpol contents in Rehmanniae Radix at various processing phases

Objective To investigate the contents of oligosaccharide and catalpol in Rehmanniae Radix at various processing phases.Methods Saccharide ingredient was extracted by ultrosonic extraction when water was used as solvent,separated by NH2 chromatographic column while acetonitrile-water(72∶28) as mobile phase at flow rate of 1.0 mL/min,detected by differential refractive detector,and assayed by HPLC.Catalpinol was extracted by ultrosonic extraction when methanol was used as solvent,separated by C18 chromatographic column while methanol-0.1% phosphoric acid(1∶9 9) as mobile phase at flow rate of 1.0 mL/min,detected at wavelength of 210 nm,and assayed by HPLC.Results There are significantdifferences at various processing phases of oligosaccharide and catalpol contents in Rehmanniae Radix.Conclusion Processing could change the content and composition pattern of oligosaccharide in Rehmanniae Radix and affect the content of catalpol in Rehmanniae Radix at the same time.