The Effect of Molecular Weight on the Antibacterial Activity of N , N , N -Trimethyl Chitosan (TMC)

• Published in: International journal of molecular sciences Vol. 20; no. 7; p. 1743
• Main Authors: Sahariah, Priyanka, Cibor, Dorota, Zielińska, Dorota, Hjálmarsdóttir, Martha Á, Stawski, Dawid, Másson, Már
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 09.04.2019; MDPI
• Subjects: acidic hydrolysis; Antibacterial activity; Antimicrobial activity; Antimicrobial agents; average molecular weight; Bacteria; Chitosan; E coli; Escherichia coli; Gram-negative bacteria; Gram-positive bacteria; Hydrochloric acid; Minimum inhibitory concentration; Molecular weight; N,N,N-trimethyl chitosan; Staphylococcus aureus; Staphylococcus infections; Studies; Temperature; antibacterial activity; chitosan; acidic hydrolysis; average molecular weight; N,N,N-trimethyl chitosan
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20071743

, , -trimethyl chitosan (TMC) with 93% degree of trimethylation was synthesized. TMC and the chitosan starting material were subjected to acidic hydrolysis to produce 49 different samples with a reduced average molecular weight (M ) ranging from 2 to 144 kDa. This was done to allow the investigation of the relationship between antibacterial activity and M over a wide M range. NMR investigation showed that hydrolysis did not affect the degree of trimethylation (DS ) or the structure of the polymer backbone. The activity of TMC against ( ) increased sharply with M until a certain M value (critical M for high activity, CMW) was reached. After the CMW, the activity was not affected by a further increase in the M . A similar pattern of activity was observed for chitosan. The CMW was determined to be 20 kDa for TMC and 50 kDa for chitosan.