Objective: To develop a HPLC method for simultaneous determination of caffeic acid, rosmarinic acid, oleanolic acid and ursolic acid in Spica Prunellae.
Method: After ultrasonic extraction with 75% ethanol solution containing 1% formic acid, the ethanol-extract of Spica Prunellae was analyzed on an Elite SinoChrom ODS-AP column using gradient elution of 0.01% phosphoric acid (A) and acetonitrile (B) at a flow rate of 0.9-1.0 mL x min(-1). A wavelength switch program was used for detection at 330 nm (0-33 min) and 203 nm (33-40 min). The column temperature was set at 20 degrees C and injection volume was 50 microL.
Result: The calibration curves of all analytes were linear. The average recoveries were 93.7%-105.2% with RSDs not more than 4.5%. The contents of caffeic acid, rosmarinic acid, ursolic acid and oleanolic acid in Spica Prunellae were 0.0401-0.0968, 0.99-2.57, 0.243-0.556, 4.06-8.13 mg x g(-1), respectively.
Conclusion: The described method is sensitive, convenient and accurate, and is suitable for the simultaneous determination of caffeic acid, rosmarinic acid, oleanolic acid and ursolic acid in Spica Prunellae.