Gracilone, a new sesquiterpene lactone from Tanacetum gracile (Tansies)

The methanolic extract of the Tanacetum gracile afforded the isolation of new sesquiterpene lactone, named gracilone (1) along with four known compounds as 14α-taraxeran-3-one (2), 14α-taraxeran-3-ol (3), apigenin (4) and β-sitosterol (5). The structure of compound 1 was elucidated on the basis of 1D, 2D NMR and MS spectroscopic analysis. Antimicrobial, antioxidant and anticancer activities of all compounds were evaluated, from which gracilone (1) showed a moderate antibacterial activity, while apigenin (4) showed comparatively more antibacterial activity against both gram­positive and gram­negative tested strains.