Guaianolides from Curcuma kwangsiensis

Three guaianoilides, including a new compound (1R,4R,5S,8S,9Z)-4-hydroxy-1,8-epoxy-5H-guaia-7(11),9-dien-12,8-olide (1) and two rare ones, (−)-gweicurculactone (2), and 2-oxoguaia-1(10),3,5,7(11),8-pentaen-12,8-olide (3), together with tricosanoic acid, and β-sitosterol were isolated from the rhizomes of Curcuma kwangsiensis S.G. Lee and C.F. Liang (Zingiberaceae). Their structures and relative stereochemistries were determined on the basis of UV, IR, MS, and 1D NMR and 2D NMR spectroscopic methods. The absolute configurations of the new compound 1 and the previously isolated compound 2 were unambiguously determined by using CD spectroscopic data.