Sesquiterpenes and other constituents from Achillea wilsoniana.

From the methanol extract of the whole plant of Achillea wilsoniana, 23 compounds were isolated. Their structures were elucidated by spectroscopic methods and chemical transformations. Three of them are new: 4E, 10E-9beta-hydroxy-3-(2-methylbutyroyloxy)-germacra-4,10(1)-diene-12,6alpha-olide (1), 4E,10E-3-(2-methylbutyroyloxy)-germacra-4,10(1)-diene-12,6alpha-olide (2) and 1beta,6a-dihydroxy-10beta-methyl-5alphaH,7alphaH-eudesm-4-one (3). In addition, 1beta-hydroxy-alpha-xyperone (5) and 9beta-acetoxy-3-(2methylbutyroyloxy)-germacra-4,10(1)-diene-12,6alpha-olide (1a) exhibited effective antibacterial activity against Staphylococcus aureus.