New Sesquiterpene Lactones from Glechoma hederacea L. and Their Cytotoxic Effects on Human Cancer Cell Lines

Three new sesquiterpene lactones, 1 alpha, 10 beta-epoxy-4-hydroxy-glechoma-5-en-olide (1), 1 beta, 10 alpha-epoxy-4,8-dihydroxy-glechoma-5-en-olide (2), and 1 beta, 10 alpha; 4 alpha, 5 beta-diepoxy-8-methoxy-glechoman-8 alpha, 12-olide (3), were isolated from the whole plant of Glechoma hederacea, together with four known sesquiterpene lactones. The structures of the three new sesquiterpene lactones were determined by spectroscopic evidence. Cytotoxic effects of the isolated compounds were examined against MDA-MB-231 (breast), HCT116 (colon), SW620 (colon), and DU145 (prostate) human cancer cell lines.