Antioxidant and antimicrobial potential of polysaccharides sequentially extracted from Polygonatum cyrtonema Hua.

We examined the antioxidant and antimicrobial attributes of Polygonatum cyrtonema Hua polysaccharides (HBSS, CHSS, DASS, CASS). The UV spectra and FT-IR results showed the purity and acidic nature of polysaccharides with β-configurations. DASS (78.585% hydroxyl radical scavenging, 92.794% ABTS radical scavenging, 75.648% DPPH radical scavenging activity, 0.582 reducing power and 98.721% Fe2+ chelation at 5mg/mL) possessed the best antioxidant potential; while, HBSS (21.113% hydroxyl radical scavenging, 14.412% ABTS radical scavenging, 28.005% DPPH radical scavenging activity, 0.285 reducing power and 48.969% Fe2+ chelation at 5mg/mL) was observed with the lowest antioxidant action. The bacterial inhibition effect of four PCHPs on Gram-positive organisms (B. subtilis and S. aureus with the maximum inhibitory diameters of 18.9 and 15.8mm, respectively) was better than that of Gram-negative bacteria (E. coli and S. typhimurium with the maximum inhibitory diameters of 10.9 and 8.4mm, respectively). The bacterial sensitivity was observed in the following order: B. subtilis>S. aureus>E. coli>S. typhimurium. The trend of antibacterial action of PCHPs was in following order: DASS>CHSS>CASS>HBSS. DASS can be considered as natural anti-oxidant as well as spoilage inhibitors to enhance the nutritive and functional values of various foods.