Nano calcium zincate-assisted synthesis of benzo[ <i>d</i> ]thiazol-2-yl phenylisoxazoles: quantum computational, <i>in silico</i> molecular docking simulations and DNA interaction

This study introduces a new and simple method for the synthesis of a series of 3-(benzo[<i>d</i>]thiazol-2-yl)-5-phenylisoxazole derivatives 3(a-f), and examines its potential interactions with DNA. The synthesis includes the reaction of 2-aminobenzenethiol (1) with a variety of substituted 5-phenylisoxazole-3-carbaldehydes 2(a-f) in the presence of a cost-effective and reusable nanocatalyst, Calcium-Zincate (CaZnO₂). The CaZnO₂ catalyst showed a consistent and long-lasting catalytic activity over several reaction cycles and retained its unique heterogeneous properties. The resulting compounds were characterized in detail using various spectroscopic and analytical techniques in order to confirm their structures. In addition, the interaction of these synthesized compounds with calf thymus-DNA (CT-DNA) using absorption spectroscopy and viscosity measurements was assessed. <i>In silico</i> docking studies were performed to predict their binding affinity with human DNA (PDB ID: 1G3X). The compounds were further analyzed using the Density Functional Theory (DFT) with the B3LYP functional and the 6-31 G(d) basis set in chloroform, with the results aligning closely with the experimental findings. Furthermore, the compounds ability to cleave PUC19 DNA was assessed, along with their photoinduced nuclease activity under UV-visible light, confirmed by photo-induced cleavage assays.