Novel eudesmanolides from the flowers of Pentanema britannicum (L.) D.Gut.Larr with antidepressant activities

From the flowers of Pentanema britannicum (L.) D.Gut.Larr., three new eudesmanolides, britannitin A (1), britannitin B (2) and britannitin C (3), as well as 17 known compounds, were successfully extracted. Compounds 1-3 were eudesmane sesquiterpene lactones with a rare -C = C- linking carbons 7 and 11. Structural determination of the separated compounds was achieved through a range of spectroscopic techniques, such as 1D and 2D NMR analyses. Compound 5β-hydroxyasperilin (HA) demonstrated the ability to ameliorate depression-like behaviours in mice induced by CSDS, suggesting its potential antidepressant effect.