Preparation and antibacterial activity of the oligosaccharides derived from Rhizoma Phragmites

In this study, we prepared Rhizoma Phragmites derived oligosaccharides (ROs) by hydrolysis with hydrogen peroxide (H2O2). The ROs yield was affected by reaction time, temperature, and H2O2 concentration. Too long reaction time and too high temperature decreased the ROs yield. Maximum ROs yield (11.26%) was obtained at reaction time 4 h, temperature 75 °C, and H2O2 concentration 3.5% (v/v). The oligosaccharides sample contained 93.16% sugar, of which the average degree was approximately 11, was water-soluble, and showed white. The ROs had the highest antibacterial activity against Staphylococcus aureus, followed by Bacillus subtilis and Escherichia coli at the concentration of 100 μg/mL.