Effects of different chemical modifications on the antibacterial activities of polysaccharides sequentially extracted from peony seed dreg.

The peony seed dreg polysaccharide (PSDPs) fractions and their modified derivatives were examined for their antibacterial potential. PSDPs along with their derivatives exhibited appreciable antibacterial activity against both Gram-positive (B. subtilis and S. aureus) as well as Gram-negative (E. coli and S. typhimurium) bacteria. Among the four polysaccharide fractions, HBSS possessed the greatest antibacterial activity with an inhibition zone of 13.6 mm against S. typhimurium, minimal inhibitory concentration of 0.12% against S. typhimurium and maximum bacterial growth inhibition. For the modified derivatives, the sulfated modified fraction (S-HBSS) exhibited the maximum antibacterial activity with inhibition zone of 15.4 mm and minimal inhibitory concentration of 0.08% against S. typhimurium, followed by carboxymethylated and phosphorylated derivatives. Out of the four tested bacteria, S. typhimurium was observed as the most sensitive strain which was inhibited most effectively by all the polysaccharide fractions. Overall, our findings clearly indicated that the selected polysaccharide fractions can be used as food ingredients with potential natural antibacterial prospective.