Extraction Of Glycyrrhiza Polysaccharide And Its Application In The Preparation Of The Antibacterial Film Containing Silver Nanoparticles

Licorice is one of the most widely used traditional herbal medicines,and about60%of prescriptions of traditional Chinese medicine containliquorice. Glycyrrhiza polysaccharide (GP) is the main active ingredientof licorice. Recently, it has attracted more and more attention for itsexcellent biological activities, and researches about licorice have beenincreasing. In this paper, we started with the extraction of GP, the effectsof the extracting conditions on the yield of GP were investigated. Thendifferent fractionated methods were applied into the fraction of GP. Inaddition, the extracted GP was applied into the synthesis of silvernanoparticles as reducing and stabilizing agent.Firstly, we investigated the effects of water/root ratio, extractingtemperature, extracting time, extracting times on the yield throughunivariate analysis. The results showed that temperature and time werethe main factors. Extracted GP presented the typical absorbance ofpolysaccharides in the FTIR and UV-Vis spectrum. The total sugarcontent was74.70%, the Mn was57758and the Mw was100956.The extracted GP was fractionated by ethanol fractionalprecipitation, quaternary ammonium salt precipitation and combination of two methods. Either of two methods can’t provide homogenousfractions because of the coprecipitation during the fractionations. But wegot a homogenous fraction through combination of two methods.The extracted GP was used in the photoinduced synthesis of Agnanoparticles by a simple, facile and green method. The prepared silvernanoparticles were characterized through UV-vis spectroscopy,transmission electron microscopy (TEM), X-ray diffraction (XRD). Thesize and size distribution varied with the concentrations of GP and silvernitrate. When the concentration of AgNO3was lower, generated particleswere less so that the GP can absorb on every crystal surface, whichleaded to quasi-spheres. With the concentration increased, the GP can’tcover all the surface of Ag particles. The formation of anisotropicnanoparticles was probably attributed to the different growth rates ofcrystallographic planes. The reaction was related to the-COOH of GP.The silver nanoparticles contained in the prepared composite filmspresent good dispersion. As the content of silver increased, the waterabsorptivity decreased and the antibacterial property films becamestronger. The obtained composite film combined the pharmacologicalactivity of GP and the antibacterial property of silver nanoparticles,which might had potential practical values in medical field.