Millifolides A–C. New 1,10-Seco-guaianolides from the Flowers of Achillea millefolium

Abstract

Ten 1,10-secoguaianolides were isolated from the flowers of Achillea millefolium. Their structures were determined on the basis of spectroscopic methods. Three of them (millifolides A-C) including two dimeric sesquiterpenoids exhibit new skeletons. Seco-tanapartholide A exhibited moderate cell growth inhibitory activity against the human cancer cell line MCF7WT (IC 50 = 5.51 μm) in vitro.