Supercritical fluid extraction assisted isolation of sesquiterpeneTI Supercritical fluid extraction assisted isolation of sesquiterpene lactones with antiproliferative effects from Centipeda minima

摘要

Pseudoguaianolide sesquiterpene lactones minimolides A (1), B (2), C (3) and D (4) and two guaianolide sesquiterpene lactones minimolides E (5) and F (6), along with seven known ones (7-13), were isolated from the supercritical fluid extract of Centipeda minima. The structures of these compounds were elucidated by extensive spectroscopic methods (IR, UV, HRESIMS, 1D-NMR and 2D-NMR), and the complete structure and stereochemistry of 1 was further confirmed by X-ray diffraction analysis. Compounds 1, 5-8, 11 and 13 displayed inhibitory activity against human nasopharyngeal cancer cells (CNE) with IC50 values ranging from 1.1 to 20.3 mu M. Compound 13 containing both alpha-methylene-gamma-lactone and alpha, beta-unsaturated cyclopentenone moieties exhibited even stronger inhibitory activity than that of cisplatin (positive control) through cell cycle arrest at G2/M phase. Isolation of six sesquiterpene lactones from Centipeda minima highlighted the potential of supercritical fluid extraction for enrichment of minor constituents for phytochemical study