Planta Med 2015; 81 - PM_118
DOI: 10.1055/s-0035-1565495

Isolation, characterisation and chemotaxonomic significance of secondary metabolites from Polygonum persicaria L.

I Lajter 1, N Kúsz 1, J Hohmann 1, A Vasas 1
  • 1Department of Pharmacognosy, University of Szeged, Szeged, Hungary

One of the largest genera of Polygonaceae is Polygonum, comprising about 300 species, primarily grows in northern temperate regions of the world. It is well known to produce a variety of secondary metabolites, such as terpenoids, flavonoids, anthraquinones, coumarins, phenylpropanoids, stilbenoids and tannins. Polygonum persicara L. is a morphologically extremely variable perennial plant, naturalized in various parts of the world. Our previous phytochemical studies revealed the presence of a new highly methoxylated flavon and three new flavonols in this species. The present work is a continuation this project with the aim of isolation and identification of secondary metabolites from this plant.

The plant materials were extracted with methanol. The extract was concentrated and then solvent-solvent partition was performed with n-hexane, and CHCl3. The CHCl3 extract was subjected to a multiple chromatographic purification (RP-MPLC, VLC, TLC, gel filtration on Sephadex LH-20 and RP-HPLC). Structure determinations were carried out by means of MS and NMR spectroscopy.

The results allowed the identification of flavanones, chalcones, an ionon-glucoside and a carboxystilbene, persilbene. 5-Hydroxy-7,8-dimethoxyflavanone, onysilin, 6-hydroxy-5,7-dimethoxyflavanone, 2'-hydroxy-3',4',6'-trimethoxychalcone, pinostrobin-chalcone and (6R,9S)-3-oxo-α-ionon-β-D-glucopyranoside, were obtained for the first time from this species. Pinostrobin and pinostrobin-chalcone, and 5-hydroxy-7,8-dimethoxyflavanone and pashanone are biogenetically related flavanones and chalcones. These compounds are chemotaxonomic markers in genus Polygonum, since the literature data suggest that, the synthesis and accumulation of flavone derivatives are not typical of other genera of Polygonaceae.

Acknowledgement: This work was supported by the Hungarian Scientific Research Fund (OTKA K109846) and a János Bolyai Research Scholarship of the Hungarian Academy of Sciences.