Polysaccharides extracted with hot water from wild Prunus spinosa L. berries

Abstract

Wild blackthorn berries represent an unexplored area in terms of the characterization of the natural biologically active polysaccharide complexes they contain. The antioxidant active fraction extracted from wild blackthorn fruits by hot water extraction (Hw) was subjected to ion-exchange chromatography and yielded six fractions by successive elution with salts. The purified fractions differed in the content of neutral sugars, uronic acids, proteins and phenolics. About 62% of the applied material was recovered from the column, with a higher yield of the fractions eluted with 0.25 M NaCl. Based on the sugar composition of the eluted fractions, several polysaccharide types were observed. The dominant components of Hw are the fractions eluted with 0.25 M NaCl (∼70%), which represent highly esterified homogalacturonan, containing up to 70-80% of galacturonic acids with a low content of rhamnogalacturonan associated with arabinan, galactan or arabinogalactan side chains, but no phenolics. Further, a dark brown polysaccharide material with a yield of ∼17% and with a high content of phenolic compounds, was eluted with alkali (1.0 M NaOH). It mainly represents an acidic arabinogalactan.

Keywords: Blackthorn fruits; Chromatography; Ion-exchange; NMR; Pectic polysaccharides; Prunus spinosa L..