الخلاصة:
Water-soluble polysaccharides extracted from the fruits of Ziziphus lotus
(Rhamnaceae), a spontaneous medicinal plant, are attracting increasing interest due to their
potential biological activities. This study aims to extract, characterize, and evaluate the
antioxidant activity of water-soluble polysaccharides obtained from the fruits of Ziziphus lotus
collected in the Ghardaïa region. The extraction was carried out by hot maceration, yielding a
mass recovery of 6.40%. Biochemical characterization of the water-soluble polysaccharide
extract from Ziziphus lotus fruits (PSZL) was performed using colorimetric methods. Total
sugars were quantified using the method of Dubois et al. (1956), protein content was
determined using Bradford's method (1976), and total polyphenols were quantified using the
Folin-Ciocalteu method. The analyses revealed contents of 73.18 ± 0.034% total sugars, 31 ±
0.05% neutral sugars, 4 ± 0.11% proteins, and 1.5 ± 0.007% polyphenols. Monosaccharide
composition analysis by thin-layer chromatography (TLC) identified the presence of
arabinose, fructose, galactose, glucose, mannose, ribose, xylose, as well as galacturonic acid
(Gal.A) and glucuronic acid (Glc.A). Antioxidant activity, assessed through DPPH• radical
scavenging assay, showed a notable effect with an IC₅₀ value of 79.51 ± 0.45 µg/mL,
indicating significant free radical neutralization potential.
