Highly oxidized sesquiterpenes from Artemisia austro-yunnanensis.

Eight new sesquiterpenes, including four guaianolides (1-4), one guaian sesquiterpene (5), one norguaianolide (6), one 1, 10-secoguaianolides (7), and one eudesmane sesquiterpene (8), along with fourteen known sesquiterpenes (9-22) were isolated from the whole plants of Artemisia austro-yunnanensis. Their structures were elucidated on the basis of spectroscopic date and HRESIMS analysis. All isolated sesquiterpenes (1-22) were evaluated their activities by the assay of LPS-induced NO production on RAW264.7, of which compounds 2-4, 9, 10 and 17 produced significant inhibition of NO production with IC50 values ranging from 2.38 to 10.67μM.