Synthesis, X-ray crystal structure elucidation and Hirshfeld surface analysis of N-((4-(1H-benzo[d]imidazole-2-yl)phenyl)carbamothioyl)benzamide: investigations for elastase inhibition, antioxidant and DNA binding potentials for biological applications

Abstract

The interest in the present study pertains to the development of a new compound based upon a benzimidazole thiourea moiety that has unique properties related to elastase inhibition, free radical scavenging activity and its DNA binding ability. The title compound, N-(4-(1H-benzo[d]imidazol-2-yl)phenyl)-3-benzoyl thiourea (C₂₁H₁₈N₄O₂SH₂O:TUBC), was synthesized by reacting an acid chloride of benzoic acid with potassium thiocyanate (KSCN) along with the subsequent addition of 4-(1H-benzo[d]imidazol-2-yl)benzenamine via a one-pot three-step procedure. The structure of the resulting benzimidazole based thiourea was confirmed by spectroscopic techniques including FTIR, ¹H-NMR, ¹³C-NMR and single crystal X-ray diffraction and further examined by Hirshfeld surface analysis. TUBC was also investigated by using both in silico methodology including molecular docking for elastase inhibition along with quantum chemical studies and in vitro experimental methodology utilizing elastase inhibition and free radical scavenging assay along with DNA binding experiments. Docking results confirmed that TUBC binding was within the active region of elastase. In comparison to the reference drug oleanolic acid, the low IC₅₀ value of TUBC also indicated its high tendency towards elastase inhibition. TUBC scavenged 80% of DPPH˙ radicals which pointed towards its promising antioxidant activity. TUBC–DNA binding by DFT, docking, UV-visible spectroscopy and viscosity measurements revealed TUBC to be a potential drug candidate that binds spontaneously and reversibly with DNA via a mixed binding mode. All theoretical and experimental findings pointed to TUBC as a potential candidate for a variety of biological applications.