Three guaianolides from Saussurea involucrata and their contents determination by HPLC.

Saussurea involucrata (Kar. et Kir.) Sch. Bip. (family Asteraceae) is a rare traditional Chinese medicinal herb. A new guaianolide, 11 beta,13-dihydrodehydrocostuslactone-8-O-[6'-O-acetyl-beta-D-glucoside] (1), together with two known guaianolides, namely 11 beta,13-dihydrodehydrocostuslactone-8-O-beta-D-glucoside (2) and 3 alpha-hydroxyl-11 beta,13-dihydrodehydrocostuslactone-8-O-beta-D-glucoside (3), was isolated from the 95% ethanol extract of the whole plants. Their structures were elucidated on the basis of spectral analysis. Their contents in the S. involucrata were determined by HPLC for the first time. Chromatographic separation was achieved on an Agilent Zorbax SB-C(18) column (250 mm x 4.6mm i.d., 5 microm) at 25 degrees C and the mobile phase was a mixture of acetonitrile and water in a mode of gradient elution detected at 209.8 nm at a flow rate of 1.0 ml/min. This method was validated in terms of selectivity, linearity, precision and accuracy. The linearity ranges were 0.066-0.44 microg for 1, 0.23-2.30 microg for 2, and 0.258-2.58 microg for 3, respectively.