RESUMEN
<p><b>OBJECTIVE</b>To develop a RP-HPLC method for simultaneous determination of orientin, isorientin, vitexin and isovitexin in Lophatherum gracile from different habitat and harvesting time.</p><p><b>METHOD</b>The HPLC method was applied and the chromatographic column was a Waters XBridge C18 column (4.6 mm x 250 mm, 5 microm). The mobile phase consisted of methanol-0.05% acetic acid (35:65). The flow rate was 1.0 mL min(-1) and the detection wavelength was set at 340 nm. The column temperature was set at 25 degrees C.</p><p><b>RESULT</b>Four components were isolated well, the linear relationships were excellent. The mean recoveries and RSD values of orientin, isorientin, vitexin and isovitexin were 103.2%, 2.1%; 101.6%, 2.7%; 98.4%, 2.3%; 99.2%, 1.8%, respectively.</p><p><b>CONCLUSION</b>The HPLC method is simple, sensitive and reliable, and can be used for the quality control of the medicinal material.</p>