Höfundar:
Sankar Rathinam, Már Másson, Martha Á. Hjálmarsdóttir, Mikkel B. Thygesen
Introduction
“Click chemistry” reactions that afford products with high yields and excellent selectivity’s eco-friendly reactions. Chitosan is a naturally abundant biopolymer that exhibits many biomedical properties due to its biocompatibility, biodegradability, and non-toxic. There have been few studies on the modification of chitosan via click chemistry.
Methods and Data
The work focused on the design and synthesis of a new class of chitosan derivatives where all C-2 primary amino groups have been converted to aromatic Chito-1,2,3-triazoles (Chitotriazolan), and common chitosan derivatives (TMC, TAC, HTC, HPC, and CMC) were synthesized with partial substitution so that remaining primary amino groups that could be converted to triazole via copper (I) catalyzed azide-alkyne cycloaddition reaction. These derivatives were characterized by IR and NMR spectroscopy. Molecular weight was determined by using size exclusion chromatography.
Results
We have synthesized chitotriazolan products by two pathways, with and without the protection of hydroxy groups with TBDMS. A previous study found that chitosan could not be converted by more than 40% from amines to triazole via N-azidated chitosan. We successfully synthesized water-soluble chitotriazolan derivatives and chitotriazolan with partially substituted common derivatives. The degree of azidation to 1,2,3-triazole was more than 90%, as confirmed by 1H-NMR. The antibacterial activity was evaluated against S. aureus, E. faecalis, E. coli, and P. aeruginosa at pH 7.2.
Conclusions
The chitosan-free amino groups were converted to azides and then to cationic chitotriazolan derivatives. The cationic chitotriazolans and mixed chitoriazolans were active against bacteria, except chitotriazolan derived from CMC, which lacked activity.