Phytochemical study of Swertia longifolia

Background: Swertia spp. (Gentianaceae) grow widely in eastern and southern Asiancountries such as Japan, China and India and are used as traditional remedy forgastrointestinal complains because of their bitter principles. Several studies have beencarried out on hypoglycemic, hepatoprotective, mono amino oxidase inhibitory andantidepressant effects of these plants and it has been shown that xanthones and iridoids areresponsible for their activities.Purpose of the study: In order to gain better knowledge of endemic plants of Flora Iranica,Swertia longifolia Boiss. growing in the northern parts of Iran, was subjected tophytochemical studies.Methods: Dried and milled aerial parts of the plant were extracted with petroleum ether andethanol of which results of petroleum ether extract has been reported previously. Forpurification of ethanol extract, it was acidified with acetic acid and subsequently extractedwith chloroform and then with n-butanol. The n-butanol extract was analyzed usingdifferent chromatographic methods and the structures of the isolated components wereestablished by means of spectroscopic techniques.Results: Four components including an iridoid glycoside (loganic acid), a secoiridoidglycoside (gentiopicroside), a secoiridoid dilactone (gentiolactone) and a nucleoside(uridine) were isolated from n-butanol extract of the plant.Major conclusion: Similar to other species of Swertia, iridoid and secoiridoid glycosidescould be considered as major constituents of Swertia longifolia Boiss.