Isolation and quantification of isofraxidin in Sarcandra glabra (Thunb.) Nakai, collected in Lam Dong province

Abstract

By various chromatographic methods, isofraxidin was isolated from the ethanol extract of the stems of Sarcandra glabra (Thunb.) Nakai collected in Lam Dong province. Its structure was elucidated by extensive spectroscopic methods including 1H-NMR, 13C-NMR, DEPT, HSQC, HMBC, and ESI-MS. A method for quantitation of isofraxidin in the plant parts of Sarcandra glabra (Thunb.) Nakai, using high performance liquid chromatography coupled with a DAD detector has been developed. The method was carried out by using a Zorbax SB-C18, 5µm (4.6 x 150mm) column with a gradient solvent system of 0.1% formic acid in water – methanol and UV-detection (340 nm). The calibration curves showed good linear regression within the concentration ranges of 2 – 125 µg/mL (r = 0.9999). The limits of detection (LOD) and quantitation (LOQ) were 0.5 and 1.5 µg/mL of isofraxidin. This method has been applied to quantify isofraxidin in some samples of roots, stems and leaves of Sarcandra glabra (Thunb.) Nakai collected in Lam Dong province. This is the first report of this compound in Sarcandra glabra (Thunb.) Nakai in Vietnam.