Sesquiterpene lactones from Achillea crithmifolia

Abstract

The isolation of three highly oxygenated guaianolides, desacetyl-1α-4α- dihydroxybishopsolicepolide [1], its 4β-hydroxy epimer 2 (a new compound), and 1β,2β:3β,4β-diepoxy-8α,10α-dihydroxyguai-12(13)-en-12,6α-olide [3], from the aerial parts of Achillea crithmifolia is reported. Because lactone 3 was shown to be identical with rupin A, the initially proposed 1α,2α:3α,4α-diepoxy stereochemistry of rupin A should be revised.