Secondary metabolites from Centaurea diluta Ait. subsp. Algeriensis (Coss. & Dur.)

The phytochemical investigation of the aerial parts of Centaurea diluta Ait. subsp. Algeriensis (Coss. & Dur.) led to the isolation of nine secondary metabolites: β-sitosterol (1), six flavonoids: eupatilin (2), jaceosidin (3), pectolinaringenin (4), galetin 3,6-dimethyl ether (5), hispiludin (6), and quercetin (9), one coumarin: scopoletin (7), and one sesquiterpene lactone: cebelin G (8). Spectroscopic methods such as 1H and 13C NMR, COSY, NOESY, HSQC, and HMBC studies, as well as comparison with literature data, were used to identify the structures. Apart from the constituents eupatilin and jaceosidin, the other compounds are new for the species Centaurea diluta Ait. subsp. Algeriensis (Coss. & Dur.). The chemotaxonomic significance of the isolates was discussed. [Display omitted] •Compounds 1, 4, 5, 6, 7, 8 and 9 are new for the species Centaurea diluta Ait. subsp. Algeriensis (Coss. & Dur.).•The structures of compounds were elucidated by spectroscopic methods.•Chemotaxonomic significance was well discussed.