Synthesis and Antioxidant Studies of 2,4-Dioxothiazolidine-5-acetic Acid Based Organic Salts: SC-XRD and DFT Approach.

In the current study, two organic salts ( and ) are synthesized, and then crystalline structures are characterized by FTIR, UV spectroscopy, and X-ray crystallographic studies. The organic salts and are optimized at the M06/6-311G(,)level of theory and further utilized for analysis of natural bond orbitals (NBOs), natural population, frontier molecular orbitals (FMOs), and global reactivity parameters, which confirmed the stability of the studied compounds and charge transfer phenomenon in the studied compounds. The studies further revealed that and are more stable than . The lowest energy merged monomer-coformer conformations were docked as flexible ligands with rigid fungal proteins and DNA receptors. The stagnant binding of the monomer through two H bonds with protein was observed for ligands and while different pattern was found with . The coformers formed a single H bond with the active site in and and a single pi-arene H interaction in . The two-point ligand-receptor interactions hooked the monomer between DNA base pairs for partial intercalation; pi stacking with additive hydrogen bonding with the base pair led to a strong benzimidazole interaction in and , whereas ethylene diamine formed weak H bonding. Thus, the molecular docking predicted that the coformer exhibited DNA intercalation reinforced by its salt formation with benzimidazole and methyl benzimidazole . Antioxidant studies depicted that has a higher IC value than that of 2,4-D and also the largest value among the studied compounds, whereas showed the lowest value among the studied compounds.