Molecular Weight Determination of Chitosan with Antibacterial Activity Using Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry Analysis

Abstract

The antibacterial effect of chitosan with different molecular weights was investigated to define their potent biological activity. Both chitosan hydrolysates designated to CTSN-P30 and CTSN-B8 derived from the hydrolysis of high molecular weight chitosan showed significant synergistic antibacterial effects toward Staphylococcus aureus in the presence of 1,3-butylene glycol. The concentration-dependent antimicrobial effect is very important in determining the minimum inhibitory concentration (MIC) of both CTSN-P30 and CTSN-B8. Each MIC50 of CTSN-P30 and CTSNB8 was determined to be about 25 and 50 μg/mL, respectively. Among chitosan hydrolysates, CTSN-P30 can effectively protect the membrane from the penetrating of fine dust which may contain unspecified microorganisms. Also, CTSN-P30, which showed very significant antimicrobial activity, was confirmed to be a hydrolysate containing (GlcNAc)3, and other hydrolysates consisting of (GlcN)5 to (GlcN)15 using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry analysis. These results demonstrated the feasibility of CTSN-P30 and 1,3-butylene glycol to use as a potent antibacterial and find a dustproof agent for the preparation of various industrial products.