Title:Obtaining Hexoses from Chitosan through Depolymerization with Nitrous
Acid
Volume: 19
Issue: 7
Author(s): Éber Eurípedes de Souza*, Adão Lincon Bezerra Montel, Robson dos Santos Barbosa, Ilsamar Mendes Soares, Miguel Daniel Noseda, Raimundo Wagner de Souza Aguiar, Tarso da Costa Alvim and Sérgio Donizeti Ascêncio*
Affiliation:
- Department of Biodiversity and Biotechnology, Amazonia Legal-Bionorte, Federal University of Tocantins, City Palmas,
Brazil
- Laboratory of Research in Natural Products, Federal University of Tocantins, City Palmas, Brazil
- Department of Biodiversity and Biotechnology, Amazonia Legal-Bionorte, Federal University of Tocantins, City Palmas,
Brazil
- Laboratory of Research in Natural Products, Federal University of Tocantins, City Palmas, Brazil
Keywords:
Chitosan, chitin, 2, 5-anhydromannose, depolymerization, nitrous acid, acetic acid.
Abstract:
Background and Objective: Residues from shrimp farming have a great potential for
sugar production and the production of derivatives for the low-carbon chemical industry. Obtainment
of bioactives from chitosan has been extensively investigated using different methodologies.
The purpose of this work was to study the chitosan depolymerization reaction aiming at the production
of monomers without the use of additional enzymes or mineral acids.
Materials and Methods: In this work, we systematically study the effect of sodium nitrite concentration
and reaction conditions (pH and temperature ranges) with acetic acid as the solvent on the
chitosan depolymerization reaction aiming at the production of monomers, specifically 2,5-
anhydromannose, without the use of additional enzymes or mineral acids.
Results: The results indicate that only a small range of reaction conditions and nitrite concentrations
allow for obtaining the monomer, while in most combinations of these parameters, oligomers are
obtained. We found that the temperature decisively affects the reaction yield, with the attainment of
2,5-anhydromannose favored at lower temperatures.
Conclusion: The method proved to be simple and easy to perform allowing to obtain 2,5-
anhydromannose with the use of low-cost reagents. This monomer can be converted into several
derivatives for industrial application (5-Hydroxymethylfurfural, ethanol, etc.)
