Preparation Of Low Molecular Weight Sulfated Chitosan And Its Antimicrobial Properties

Chitosan is the wide existence macromolecule amylose in the nature, have the good biological compatibility with other organism, and also has a variety of biological activities and rich source. Thus in food, medicine, chemical industry, and agriculture have broad application prospects, becoming one of the hot researches in recent years.Choose the chlorosulfonic acid as sulfonation reaction reagent of the low molecular chitosan. By orthogonal experiments, determined the optimum reaction conditions are as follows:chlorosulfonic acid dosage is lOmL; sulfonation reaction temperature is90℃; Sulfonation reaction time is4h.Infrared Spectroscopy showed that the be used sulfonation reaction method can effective import the-SO3-group, its characteristic peaks are located at1250cm-1and800cm-1around, Sulfonated products of the degree of substitution of up to9%. Compare the infrared spectra of the heparin and sulfated chitosan can be seen that between the two spectra in the characteristic peak position is very similar, so prove the existence of-SO3-groups and its structure similar to heparin.Using chitosan-standard goods and sulfated chitosan, in accordance with different concentrations of sulfonated chitosan antibacterial test methods under different reaction were measured inhibition zone diameter size, results showed that chitosan and three kinds of low molecular weight sulfated chitosan has a certain amount of antimicrobial activity, and the weakest antimicrobial activity of chitosan with molecular weight of the measured solution concentration and its antimicrobial activity also increased. Sulfonated chitosan molecular weight of its antibacterial activity has a great impact, low molecular weight sulfated chitosan antimicrobial activity is stronger than too large molecular weight of sulfonated chitosan antimicrobial activity.