Sesquiterpene lactones from Inula helianthus-aquatica

To investigate the sesquiterpene lactones of the aerial parts of Inula helianthus-aquatica.Compounds were isolated and purified by silica gel, Sephadex LH-20 and preparative HPLC. On the basis of physicochemical properties and spectroscopic data, their structures were identified.Seven sesquiterpene lactones and four other compounds were obtained and identified as 2-desoxy-4-epi-pulchellin (1), 6-acetoxy-4-hydroxy-1, 10H-pseudoguaia-11 (13)-en-12,8-olide (2), 4-acetoxy-6-hydroxy-1, 10H-pseudoguaia-11(13)-en-12,8-olide (3), 8-epi-inuviscolide (4), 2,3,11,13-tetrahydroaromaticin (5), 11,13-dihydro-ergolide (6), 4-epipulchellin-2-O-acetate (7), 7-epiloliolide (8), loliolide (9), beta-sitosterol (10) and daucosterol (11).All the compounds were isolated from this plant for the first time.