[Two new sesquiterpene lactones from Syneilesis aconitifolia]

The chemical constituents from Syneilesis aconitifolia were investigated by comprehensive column chromatography techniques, including silica gel, ODS, Sephadex LH-20, and semi-preparative high performance liquid chromatography, and six compounds were isolated from the methanol extract of S. aconitifolia. Their structures were identified by NMR, HR-ESI-MS, and single crystal X-ray diffraction and the compounds were named saconitifolia C(1), saconitifolia D(2), 3β-angeloyloxy-6β-hydroxy-8-epi-eremophilenolide(3), 6β-hydroxy-8β-methoxyeremophil-7(11)-12,8α-olide(4), 8βH-eremophil-3,7(11)-dien-12,8α(14,6α)-diolide(5), 8β-hydroxyeremophil-3,7(11)-diene-8α,12(6α,15)-diolide(6), 8β-methoxyeremophil-3,7(11)-diene-8α,12(6α,15)-diolide(7), and 3β-angeloyloxy-6α,15-epoxy-10βH-eremophil-7(11)-en-12,8β-olide(8). Compounds 1-8, including two new compouds(1 and 2), were sesquiterpene lactones, and compounds 3-8 were isolated from S. aconitifolia for the first time. All of the compounds showed no cytotoxic activity on HeLa or GL261 cells.