Partial Characterization and Hydrolysis Procedure of Water Soluble Polysaccharides Extracted from Onesaharian Medicinal Plant: Malvaaegyptiaca L.

Malvaaegyptiaca L. (Malvaceae), a spontaneous plant used as a traditional medicine in Ghardaia (SeptentrionalSahara Algerian). This paper reports the extraction and partial characterization of water-soluble polysaccharides from M.aegyptiaca 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 1.46% (w/w). The crude water soluble polysaccharide extracts were further characterized and revealed the average values 17.14 ± 1.43% proteins and 78.18±2.04% carbohydrates, among them 30.68±0.42% are uronic acid and47.49±1.62%are neutralmonosaccharides.The acid hydrolysis was studied with trifluoroacetic acid (TFA) at two concentrations,with five durations of hydrolysis and at two temperatures. A single hydrolytic step with 4M TFA at 80°C for 4 h is suggested to be more effective in releasing monomers frompolysaccharides than other hydrolysis procedures.The identification of monosaccharide composition by high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) methods shows 56.86% of galactose, 8.46% of rhamnose, 9.04% of arabinose, 5.05% of mannose and 20.57% of glucuronic acid.