Spectroscopic and Theoretical Elucidation of Acylthiourea Derivatives with Antioxidant and Low-Toxicity Profiles

Abstract

Acylthiourea derivatives, N-[(6-chloro-1,3-benzothiazol-2-yl)carbamothioyl]benzamide (1) and N-(pyrimidin-2-ylcarbamothioyl)benzamide (2) were prepared and characterized. Electronic structures of compounds 1 and 2 were optimized by employing density functional theory (DFT) calculations under gas phase conditions. Molecular properties such as HOMO-LUMO energy, chemical reactivity descriptors, and molecular electrostatic potential (MEP) were calculated using the BP86 method and the def2-TZVP basis set. In silico ADME/Tox profile analyses were performed on compounds using the web tools SwissADME and pkCSM webserver. The radical scavenger activity of 1 and 2 was determined by in vitro assays such as DPPH and ABTS⁺ scavenger activities. These compounds exhibit significant radical scavenger potential in the ABTS assay, demonstrating superior activity to the reference antioxidant Trolox. In the V79 cell line, the inhibitory effects of compounds 1 and 2 were negligible within the tested dose range and did not result in significant DNA damage. The acute toxicity of compounds was also evaluated in mice. A single administration of compounds 1 and 2 (50 mg/kg and 300 mg/kg) did not cause mortality, behavioral alterations, or significant changes in liver and kidney biomarkers in mice. At the same time, oxidative stress parameters were modulated dose- and tissue-dependent. Compound 1 increased catalase activity in the liver without inducing oxidative damage, whereas compound 2, at 300 mg/kg, elevated lipid peroxidation in the kidneys and altered catalase activity in both kidney and brain tissues, suggesting a tissue-specific redox response. Docking simulations revealed a high binding affinity of the compounds to key antioxidant enzymes.