Design, Synthesis, and Fluorescence Properties of Bis-Schiff Base Derivatives Via Spectroscopic, Computational, and Docking Approaches.

This study emphasises the Synthesis of novel bis-Schiff base derivatives via the condensation reaction of two different aldehydes with a aromatic diamine. This reaction was carried out between p-phenylenediamine with 4-chlorobenzaldehyde and 2,4-dichlorobenzaldehyde. The study will explain the structural comparison between the compound PP4CLB and PP24CLB. The synthetic compounds' configurations were verified by DFT calculations, and their structural integrity was verified by NMR, Raman, and IR spectroscopy. To provide a detailed characterisation of molecular properties, the study included a wide range of analyses, such as the assessment of molecular electrostatic potential, frontier molecular orbitals, and HOMO-LUMO energy gaps. For our molecular docking analysis, we used the Tdp1 catalytic domain in complex with an inhibitor (PDB ID: 6W7J) protein as the target. Both PP4CLB and PP24CLB used the same protein structure. The docking results indicated that PP24CLB demonstrated a marginally superior binding affinity (-8.03 kcal/mol) relative to PP4CLB (-7.89 kcal/mol). The interaction analysis showed that both ligands made several stabilising connections in the active site of 6W7J. PP24CLB had two hydrogen bonds and other non-covalent interactions. On the other hand, PP4CLB had other non-covalent interactions. The PASS prediction showed that our compound is very likely to have biological activity, with a Pa value of 0.849. This Pa score means that the compound is very likely to work as a Glycosylphosphatidylinositol phospholipase D (GPI-PLD) inhibitor.