CARACTÉRISATION PARTIELLE DES POLYSACCHARIDES HYDROSOLUBLES DES FEUILLES D'Asphodelus tenuifolius CAVAN (LILIACEAE): EFFET PRÉBIOTIQUE DES OLIGOSACCHARIDES ISSUS DE L'HYDROLYSE DES POLYSACCHARIDES

Abstract

Asphodelus tenuifolius Cavan. (Liliaceae), a spontaneous plant used as a traditional medicine in Ghardaïa (Septentrional Sahara Algerian). This paper reports the extraction and partial characterization of watersoluble polysaccharides from A. tenuifolius leaves. These polysaccharides were obtained by elimination of the ethanol extract and sequential extraction in distilled water, followed by precipitation in 75% ethanol. The yield of extract is 0.65% (w/w). The crude water soluble polysaccharide extracts were further characterized and revealed the average values 18.33±2.08% moisture, 23.66±1.52% ash, 26.13±0.37% proteins and 28.96±1.12% carbohydrates, among them 32.49±0.26% are uronic acid and 67.50±0.94% are neutral monosaccharides.The acid hydrolysis 4M TFA at 80°C for 5 h is suggested to be more effective in releasing monomers. Thin layer chromatography (TLC) analysis of hydrolysat shows that the extract is constituted of heteropolysaccharides acid. The identification of monosaccharide composition by high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) method shows 39.25% of mannose, 31.55% of glucose, 10.92% of glucuronic acid, 8.9% of arabinose, 5.22% of rhamnose and 4.14% of xylose. The partial hydrolysate stimulate significantly for 0,1 DO after 24 hours, the multiplication of Klebsiella pneumonea pneumonea and prebiotic effect of the oligosaccharides from these hydrolysates on this are very likely.