Several Astragalus species are used in Bulgarian folk medicine as a diuretic for a treatment of hypertension, renal disorder, nervous diseases, rheumatism, as well as a diaphoretic. In previous study we announce on the identification of three flavonol aglicones and six flavonol glycosides from the overground parts of A. ponticus Pall. and A. corniculatus Bieb.
In the present work, we report the isolation and identification of other compounds from this species.
The plant material was collected during the flowering period (July, 1997) in Northern part of Bulgaria. Dried aerial parts were extracted with EtOH (50%). The extract was evaporated and the aqueous residue was treated with CHCl3 and EtOAc consecutively. Among the isolated compounds were b-sitosterol from CHCl3 extract and flavonoids isolated from the EtOAc extract by different chromatographic techniques - column chromatography (Cellulose; Sephadex LH-20; Polyamide), preparative thin layer (TLC) and paper chromatography (PC). TLC was performed on Kieselgel G F254, type 60, (Merck). Final purification was carried out on Sephadex LH-20 with methanol eluation.
The substances are identified by comparison of TLC with that of authentic samples, acid hydrolysis, UV and IR- spectral analysis with diagnostic shift reagents such as: quercetin-3-glucoside (isoquercitrin), kaempferol-3-rutinoside, b-sitosterol in A. ponticus and kaempferol-3-glucoside (astragalin), isorhamnetin-3-glucoside in A. corniculatus.
All compounds are new for A. corniculatus Bieb and A. ponticus Pall.