Determination of astragaloside IVand isoflavoniods from Gansu Astragalus membranaceus

Objective To determine the contents of astragaloside Ⅳand isoflavoniods in Gansu Astragalus membranaceus. Methods RP-HPLC on a Kromasil ODS-1 column(5 μm, 4.6 mm × 250 mm) was employed, and astragaloside Ⅳ was detected by evaporative light scattering detector in a gradient of methanol-water at eluent gas rate of 2.0 mL/min and under a drift tube temperature of 80 ℃. Formononetin and calycosin were also eluted in a gradient of methanol-water, but detected by photodiode array detector at a wavelength of 254 nm. Results The concentration range of astragaloside Ⅳ, formononetin and calycosin was 8.06-28.2 μg/mL, 2.35-47.0μg/mL and 2.32-46.5 μg/mL respectively, and correlation coefficient0.9938. Conclusion We established a simple and practical method for determining the contents of above three compounds.