HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF TRIPTONIDE, TRIPTRIOLIDE, AND TRIPTOPHENOLIDE IN ETHYL-ACETATE EXTRACT OF TRIPTERYGIUM-WILFORDII HOOK F

To monitor the composition of extracts of the Chinese herbal remedy Tr ipterygium wilfordii Hook F (TwHF), a rapid selective, and sensitive r everse phase HPLC method was developed for the quantitative determinat ion of some of the major or active diterpenoid components, triptonide (1), triptophenolide (2), and triptriolide (3). Ethyl acetate extracts ; of TwHF were extracted with chloroform, filtered, and then purified by passage through mixed columns of silica gel and alumina B for 1 and 2, and an alumina B cartridge for 3. The columns were eluted with eth yl acetate:chloroform, 1:9, for 1 and, 3:7, for 2. The alumina B cartr idge was washed with ethyl acetate : chloroform, 1 : 9 and then 3 was eluted with ethyl acetate : methanol, 8:2. The elutions were chromatog raphed on a silica-based reverse phase HPLC Cls column with the mobile phase of water : acetonitrile, 67 : 33, 54 : 46, and 86: 14 for 1, 2, and 3, respectively, with UV detection performed at 218 nm. Linear de tection responses were observed for the calibration curves in the conc entration ranges of 0.64-20.48 mg/L for 1, 4.04-60.60 mg/L for 2, and 0.31-19.84 mg/L for 3. The average recoveries were 96.88%, 102.54%, an d 100.09%, and the limits of quantitation were 0.174 mg/L, 0.049 mg/L, and 0.112 mg/L for 1, 2, and 3, respectively.