Simultaneous quantification of two flavonoids in morus alba by high performance liquid chromatography coupled with photodiode array detector

Abstract

The root bark of Morus alba L. (Family: Moraceae) is an important medicinal herb in many countries and has long been used as a traditional medicine for the treatment of cough, fever, blood pressure reduction, and respiratory diseases. In the present study, the simultaneous determination of two flavonoids, kuwanon G and morusin, for quality control of M. alba was conducted using high-performance liquid chromatography (HPLC) equipped with photodiode array (PDA) detector. The column used for separation of kuwanon G and morusin was a Gemini C18 analytical column maintained at 45°C. The mobile phase for efficient separation of two analytes was flowed 0.1% (v/v) aqueous formic acid-acetonitrile with gradient elution. The detection wavelength for quantification was set at 266 nm. The optimized method showed good linearity with coefficients of determination of 0.9998 within the tested concentration ranges. The limits of detection for the two flavonoids, kuwanon G and morusin, were 0.69 μg/mL and 0.35 μg/mL and the limits of quantification of kuwanon G and morusin, were 2.10 μg/mL and 1.07 μg/mL. The recoveries were 98.40-111.55% and the relative standard deviation (RSD) value was within 3.50%. The RSD values of intra- and interday precisions were 0.08-0.70% and 0.06-0.48%, respectively. The amounts of kuwanon G and morusin were 1.94-2.26 mg/g and 1.05-1.12 mg/g. The established HPLC-PDA method will help to improve the quality control of M. alba and related products.