High Performance Liquid Chromatographic Determination of Triptolide and Tripdiolide in an Ethyl Acetate Extract ofTripterygium wilfordii Hook F.

Abstract A new analytical method for the determination of triptolide and tripdiolide in ethyl acetate extracts of Triterygium wilfordii Hook F. is described. The procedure consists of preliminary enrichment by Sep-Pak alumina B cartridge chromatography followed by HPLC analysis. HPLC is performed with a stainless steel column packed with Nova-Pak C18, using acetonitrile-water (19 : 81) as a mobile phase for triptolide and acetonitrile-water (11 : 89) for tripdiolide. The effluent is monitored by ultraviolet detection at 214 nm. Quantitative analysis of triptolide is then carried out by comparison to an internal standard, and of tripdiolide by the external standard method. The amounts of triptolide and tripdiolide per 100 mg of the ethyl acetate extract were determined to be 19.88 ug and 9.58 ug respectively. The method is sufficiently sensitive and specific to assay the diterpenes found in Tripterygium wilfordii Hook F. accurately.