Pharmacological screening of Polygonaceae species and isolation of biologically active compounds from Rumex aquaticus L. and Rumex thyrsiflorus Fingerh

A few years ago, the research group of the Department of Pharmacognosy at the University of Szeged started a screening programme to investigate the pharmacological activities of species belonging to the family Polygonaceae and to identify the bioactive compounds of the selected plants. In the course of the work, different pharmacological screenings were performed with plants of the Polygonaceae family, especially members of the genus Rumex. The main results of the present work were: • A publication relating a review of the literature on the genus Rumex, from aspect of the chemistry and pharmacological properties of the plants. • Extraction of plant materials of Rumex species with various solvents for the screening, and investigation of the xanthine oxidase inhibitory and antibacterial activities of the extracts: o Mainly the n-hexane and CHCl3 extracts, prepared from the roots of the plants, displayed high antibacterial activity. o The CHCl3 extracts and/or the remaining aqueous MeOH fractions demonstrated the highest XO inhibitory activity. • Identification of 19 bioactive secondary metabolites of Rumex aquaticus: isolation, structure elucidation and in vitro evaluation of antibacterial, XO-inhibitory and neuroprotective potentials of the extracts and the isolated compounds: o The naphthalene-derivatives exerted remarkable antibacterial effects. o The flavonoid-aglycons and some of the anthraquinone-derivates showed activity against xanthine-oxidase. o The neuroprotective properties of quercetin-3-O-arabinoside and quercetin-3-O-galactoside were evaluated. • Phytochemical and pharmacological analysis of Rumex thyrsiflorus: isolation and structure determination of 4 compounds and in vitro antibacterial evaluation of the extracts and compounds