Study of In Silico Binding Interactions and In Vitro Biosorption of Type A Trichothecenes Using Devil Fish Chitosan

Trichothecenes are the most common Fusarium mycotoxin contaminants of grains and their related products. Searching for effective adsorbents remains a major challenge in mycotoxicology, due to the low polarity and bulky chemical structure of type A trichothecenes. This study aimed to investigate in silico chitosan binding to type A trichothecenes such as diacetoxyscirpenol (DAS), neosolaniol (NEO), T-2 toxin (T2), and HT-2 toxin (HT2) and to study in vitro the devil fish chitosan biosorption capacity under two pH conditions (pHs 3 and 8). Molecular dynamic experiments showed that the chitosan monomers D-glucosamine and N-acetyl-D-glucosamine mostly bound to trichothecenes through the O in hydroxyls and glycosidic bonds and through their functional groups containing nitrogen. DAS exhibited a 9.44-, 6.39-, and 4.54-fold increase in the number of intermolecular contacts with chitosan compared to NEO, HT2 and T2, respectively. Moreover, in vitro experiments showed that at pH 3, chitosan exhibited a significant DAS sorption efficiency of 31.60% (p < 0.005), corresponding to a mass-normalized sorption capacity of 126.4 ng/mg. In contrast, no significant differences in sorption were observed at pH 8 (p > 0.05). Regarding NEO, T2, and HT2, no significant adsorption was detected under either pH condition (p > 0.05). This study is the first attempt to elucidate chitosan's capacity to bind DAS and propose a mechanism for that interaction.