Selenocyanate-functionalized chitosan derivatives: Preparation, characterization, and evaluation of antioxidant...

This work describes the preparation of chitosan derivatives grafted with selenocyanate functional groups through a nucleophilic substitution reaction, with the objective of improving both their water solubility and antioxidant performance. Organic selenocyanate compounds were generated by reacting nicotinic acid and isonicotinic acid derivatives with 3-selenocyanatopropylamine, which were subsequently grafted onto chitosan molecules through nucleophilic substitution. The structures of the derivatives and their selenium content were characterized using Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (¹H NMR), and inductively coupled plasma mass spectrometry (ICP-MS). In vitro evaluation confirmed the superior antioxidant activity of the synthesized derivatives. Specifically, they exhibited excellent DPPH radical scavenging rates of over 70 % at 0.4 mg/mL, indicating a significant enhancement compared to native chitosan. Cytotoxicity assays (MTT method) indicated that most derivatives possessed good biocompatibility. In particular, derivatives 3a, 3b, 3f, and 4c showed cell viability rates above 80 % within the tested concentration range, suggesting their potential as novel antioxidants and selenium supplements. This study offers a novel approach to broaden the utilization of chitosan in food, nutraceutical, and pharmaceutical applications.