DFT analyses of arsylsemicarbazone group as functional compound for application as excellent fluorescent probes and medicament: study on virtual screening through molecular docking

The present invention reports two novel functional compounds, 2-hydroxy-3-naphthaldehyde thiosemicarbazone (2H3NTS) and 2-hydroxy-3-naphthaldehyde semicarbazone (2H3NS), as plausible fluorescent probes possessing excited state intramolecular proton transfer property, and they are not yet reported to be synthesized by any research group. The DFT study reveals significantly higher Stokes shift (31,476 cm⁻¹) for 2H3NS indicating swift relaxation from initial to the emissive state and reduces self-quenching from self-molecular absorption which favours its practical application. Consequently, successive in vitro activity of 2H3NTS and 2H3NS is studied in silico using molecular docking towards the inhibition capacity of target kinase protein like CDK, primarily responsible for cell growth. As expected, 2H3NS is capable of binding with both competitive ATP binding SITE I and non-competitive SITE II which lies below the T-loop, thereby inhibiting the cell growth and differentiation. However, 2H3NTS with polarizable sulphur is incapable of binding at SITE I with selective inhibition posing the ATP site to be well conserved.