One-Pot Chitin Conversion to High-Activity Antifungal N,N-Dimethyl Chitosan Oligosaccharides

Chitosan oligosaccharide and its derivatives are known for their diverse biological activities. In this study, we communicate a convenient one-pot synthesis of N,N-dimethyl chitosan oligosaccharide (DMCOS) from chitin via acid-catalyzed tandem depolymerization-deacetylation-N-methylation pathway using formaldehyde as the methylation reagent. The synthesis protocol offers 77 % DMCOS that features a high degree of deacetylation, a high degree of methylation, and a low average molecular weight. Compared to chitosan, DMCOS exhibits superior antifungal activity against Candida species. Mechanism study reveals a previously non-reported hydroxyl group-assisted effect that facilitates the reductive amination reaction under strong acidic conditions. Overall, our findings demonstrate the feasibility of direct synthesis of DMCOS from chitin, highlighting its potential use in anti-fungal applications.

Automated summary

This study presents a convenient method for the synthesis of N,N-dimethyl chitosan oligosaccharide (DMCOS) from chitin. The synthesis protocol involves acid-catalyzed tandem depolymerization-deacetylation-N-methylation reactions using formaldehyde as the methylation reagent. The resulting DMCOS exhibits a high degree of deacetylation, a high degree of methylation, and a low average molecular weight, and shows superior antifungal activity against Candida species compared to chitosan.