Three new acylated flavone C-glycosides from the flowers of Trollius chinensis

Three new flavone C-glycosides with the substitution of the unusual acyl, 2''-O-veratroylisoswertisin (1), 3''-O-2-methylbutyrylisoswertiajaponin (2), and 3''-O-2-methylbutyrylvitexin (3), together with the known compounds of 2''-O-2-methylbutyrylisoswertisin (4), 3''-O-2-methylbutyrylisoswertisin (5), and trollisin I (6) were isolated from the antibacterial fraction of the aqueous extract of the flowers of Trollius chinensis. The structural elucidations of these compounds were carried out by a detailed analysis of the NMR and MS spectra.