Abstract
Three xanthones were isolated from petroleum ether extract of the aerial parts of the herb, Swertia longifolia, an endemic plant of Flora Iranica. The structures were confirmed by various spectroscopic methods (UV; IR, 1H-NMR, 13C-NMR and MS) as swerchirin (1,8-dihydroxy-3,5-dimethoxyxanthone), swertiaperenine (1,8-dihydroxy-2,6-dimethoxyxanthone), and gentiacauleine (2,8-dihydroxy-1,6-dimethoxyxanthone).