Scorpiofauna as an alternative source of chitin and chitosan: Taxonomic influence on physicochemical properties.

The Moroccan scorpion fauna currently comprises 61 species, characterized by the existence of a chitinous exoskeleton. Most studies on chitin and chitosan extraction have been limited to marine species. In the present study, we conducted for the first time a comparative investigation of two newly studied scorpion species ( Androctonus mauritanicus and Scorpio mogadorensis ) as sources of chitin and chitosan. An extraction process was used, including demineralization, deproteinization, bleaching and deacetylation. Various physicochemical characterizations using FTIR, SEM, XRD NMR, TGA/DSC, ICP-OES, Potentiometry and Viscosimetry were performed. The results showed that chitin was extracted with yields of 16.93% and 15.60%, while chitosan was obtained with yields of 62.72% and 76.87% for A. mauritanicus and S. mogadorensis , respectively. XRD analysis revealed a decrease in crystallinity after deacetylation, with chitosan exhibiting indices of 46.15% and 49.14%. The degree of deacetylation varied depending on the method, reaching up to 99.00% and 89.55% by ¹H NMR. In addition, the obtained chitosan showed molecular weights of 102 kDa for A. mauritanicus and 65 kDa for S. mogadorensis , with good viscosity and solubility in dilute acetic acid (1%). These results highlight the influence of taxonomic origin on the structural and physicochemical properties of chitosan and demonstrate that Moroccan scorpions represent a promising alternative terrestrial source of high-quality chitosan.