Quantitative analysis of quercetin in Euphorbia helioscopia L by RP-HPLC

Euphorbia helioscopia L is widespread in China and has a large number of flavonoids. Quercetin glycosides, having useful biological activities, are abundant in this plant, and no validated analytical method has so far been developed for their determination. We, therefore, standardized a reversed-phase high-performance liquid chromatography (RP-HPLC) assay for quercetin detection. For this, the plant was locally procured and identification was confirmed based on its morpho-histological characteristics. Ethyl acetate extracts of leaves, stems, and roots were analyzed by RP-HPLC using Agilent 1120 HPLC TC-C(18) column (250 × 4.6 mm; 5 μm) with UV-detector system. The mobile phase of methanol-0.2% phosphoric acid (65:35) solution was used with the flow rate of 1.0 ml min(-1) at 30°C, and the detection was performed at 360 nm wavelength. Our data show that the linear range of quercetin was 0.025-0.150 mg.ml(-1) (r = 0.9995; n = 6) with the recovery rate of 97.50-103.30% (average 100.40%; RSD = 2.28%). The target component was baseline separated during only the period of 9 min. The repeatability of RP-HPLC analysis was demonstrated with an RSD of 1.77% (n = 6), and the highest quercetin content (average 1.42 mg g(-1)dry-weight) was present in leaves. It was, therefore, concluded that RP-HPLC is a simple, rapid, accurate, and sensitive method for the detection of quercetin from Euphorbia helioscopia L.