Glycerol group substituted bis(2-pyridylimino)isoindoline (BPI) complexes: synthesis, characterization and investigation of their biological properties

In this study, a glycerol group substituted bis(2-pyridylamino)isoindoline (BPI-OH) ligand and its metal complexes (M = Pt, Cu and Co) were synthesized. Characterization of all new compounds was carried out using FT-IR, NMR, UV-Vis, and mass spectroscopy. Various biological activities of BPI derivatives were also tested. The antioxidant activities of BPI-OH, Pt-BPI-OH, Cu-BPI-OH, and Co-BPI-OH were 87.52 ± 4.62%, 98.05 ± 5.61%, 92.20 ± 5.12%, and 89.27 ± 4.74%, at 200 mg L⁻¹ concentration respectively. BPI derivatives displayed perfect DNA cleavage activity and plasmid DNA was completely broken at all tested concentrations. The antimicrobial and antimicrobial photodynamic therapy (APDT) activities of the compounds were investigated and BPI derivatives showed good APDT. E. coli cell viability was inhibited at 125 and 250 mg L⁻¹. BPI-OH, Pt-BPI-OH, Cu-BPI-OH, and Co-BPI-OH also successfully inhibited the biofilm formation of S. aureus and P. aeruginosa. Furthermore, the antidiabetic activity of BPI derivatives was studied. This study also evaluates the binding affinities of four compounds (BPI-OH, Pt-BPI-OH, Cu-BPI-OH, and Co-BPI-OH) to various residues of DNA using hydrogen bond distance measurements and binding energies. The results show that the BPI-OH compound forms hydrogen bonds with residues in the major groove of DNA, while BPI-Pt-OH, BPI-Cu-OH, and BPI-Co-OH compounds form hydrogen bonds with residues in the minor groove. The hydrogen bond distances for each compound range from 1.75 to 2.2 Angstroms.