[Isolation and determination of Neoechinulin A in Cordate Pinellia Tuber].

The Neoechinulin A in Cordate Pinellia Tuber was isolated by column chromatography and identified by mass spectrometry and nuclear magnetic resonance (NMR). A method of reversed-phase high performance liquid chromatography (RP-HPLC) for the determination of the Neoechinulin A in Cordate Pinellia Tuber was developed. The chromatography was performed on a Diamonsil C18 column (250 mm x 4.6 mm, 5 microm) with a mixture of methanol and 0.1% phosphoric acid solution (63:37, v/v) as mobile phase at a flow rate of 1.0 mL/min. The detection wavelength was set at 225 nm and the column oven temperature was set at 30 degrees C. The volume of injection was 10 microL. There was a good linear relationship (r = 0.9995) between the mass concentration and the peak area of Neoechinulin A in the range of 2.0 - 40.0 mg/L. The recovery was 98.3% - 101.1%. The method is rapid and simple with good accuracy, reproducibility and suitable for the quality control of Cordate Pinellia Tuber from different sources.