ABSTRACT
Objective: To establish an HPLC method for determination of baicalin and wogonoside contents in Xiaochaihu decoction. Methods: Decoction pieces were mixed and decocted with water. The chromatographic column was Agilent Zorbax XDB-C18 (150 mmX4.6 mm, 5 μm); the mobile phase was composed of 0.2% phosphate acid-water(A) and acetonitrile (B) with gradient elution at a flow rate of 1 ml/min. The detection wavelength was set at 275 nm, the temperature of column was 25°C, and the injection volume was 15 μL. Results: Baicalin and wogonoside were separated at baseline within 30 min with good linearity; the standard curves for baicalin and wogonoside were Y=44.16X-36.22 (r=0.999,9) and Y=52.08X-28.69(r= 0.999,9), respectively. The intra-day and inter-day precisions were both less than 1%, and the limits of qualification were 0.615,6 μg/ml for baicalin and 0.220,8 μg/ml for wogonoside. The recovery rates (n = 6) were 95.73% (RSD = 0.8%) for baicalin and 97.02% (RSD= 1.56%) for wogonoside. Conclusion: The method is simple, accurate, stable, and reliable in determining the contents of baicalin and wogonoside in Xiaochaihu decoction, and it can be used for the quality control of this preparation.
ABSTRACT
Objective: To determine the contents of calycosin-7-O-β-D-glucoside and formononetin in Astragalus membranaceus (Fisch.) Bge. by high performance liquid chromatography (HPLC). Methods: The HPLC condition was as follows: column: Hypersil ODS 2 column (4.6 mm×250 mm, 5 μm); mobile phase: A was ACN-MeOH (9 : 1,V /V), B was H2O, with gradient elution; flow speed: 1.0 ml/min; detection: 260 nm; temperature of column: room temperature; injection volume: 20 μl. Astragalus membranaceus (Fisch.) Bge. was extracted with methanol solution twice, each time 20 min. Results: The theoretical plate numbers of calycosin-7-O-β-D-glucoside and formononetin were 50 134 and 25 258, respectively. The calibration curves were linear within the range of (2.022-101.1) μg/ml for calycosin-7-O-β-D-glucoside and (38.04-1522) μg/ml for formononetin, with their regression function being Y=58 924X - 12 352, r=0.999 9 and Y=9 237X - 124 447, r=0.999 9, respectively. The intra-day and inter-day precisions (RSD) at low, middle and high injection volume were all less than 2.0%. The limits of detection were 0.202 2 mg/ml for calycosin-7-O-β-D-glucoside and 1.522 mg/ml for formononetin. The recovery rates were 98.34% (RSD=1.33%, n=3) for calycosin-7-O-β-D-glucoside and 98.84% (RSD=0.12%, n=3) for formononetin. The contents of calycosin-7-O-β-D-glucoside and formononetin in 10 different batch of Astragalus membranaceus (Fisch.) Bge. were determined. Conclusion: HPLC is a simple and reliable method for determining the contents of calycosin-7-O-β-D-glucoside and formononetin in Astragalus membranaceus (Fisch.) Bge.