Determination of five components in Ixeris sonchifolia by high performance liquid chromatography.

A high performance liquid chromatography (HPLC) method was developed for the simultaneous quantification of five major active ingredients (markers) in Ixeris sonchifolia (Bge.) Hance, namely chlorogenic acid, caffeic acid, luteolin-7-O-beta-D-glucuronide, luteolin-7-O-beta-D-glucoside and luteolin. Samples were extracted with 70% methanol. The chromatographic separation was performed on a Hypersil ODS(2) column (250 mm x 4.6 mm i.d.; 5 microm) with a gradient of acetonitrile and 0.5% (v/v) aqueous acetic acid, at a flow rate of 1.0 ml/min, detected at 335 nm. Five regression equations showed good linear relationships (r(2)>0.999) between the peak area of each marker and concentration. The assay was reproducible with overall intra- and inter-day variation of less than 3.2%. The recoveries, measured at three concentration levels, varied from 94.1% to 100.7%. This assay was successfully applied to the determination of the 5 bioactive compounds in 18 samples. The results indicated that the developed assay method was rapid, accurate, reliable and could be readily utilized as a quality control method for I. sonchifolia (Bge.) Hance.