Pharmacologically bio-relevant N-functionalized homo-binuclear macrocyclic complexes: synthesis, spectral studies, biological screening, HSA binding, and molecular docking

Abstract

The bio-efficient homobinuclear macrocyclic complexes, [Co₂LCl₄] · 2H₂O (1), [Ni₂LCl₄] · 2H₂O (2), [Cu₂LCl₄] (3) and [Zn₂LCl₄] · H₂O (4); Tetrachloro[1,1' biphenyl bis(1,6,9,14-tetrahydro-3,4;11,12-diphenyl-1,6,9,14-tetraazacyclohexadecane)] di metal(II).nH₂O, were synthesized via metal ion controlled reaction using 3,3′-diaminobenzidine, 1,2-bis(bromomethyl)benzene and ethane-1,2-diamine. The stoichiometry, geometry, thermal stability and morphology of the synthesized compounds were inferred by analytical and spectral data. The complex 3 showed substantial radical scavenging potency. The metal complexes were also screened for comparative antibacterial analysis against different pathogenic microbes. XTT reduction assay further certified this observation to resist biofilm formation. Further, various biophysical measurements were performed for the assessment of human serum albumin-binding affinity of complexes 1-4.

Keywords:

• 3,3′-Diaminobenzidine
• spectral characterization
• XTT reduction assay
• HSA-binding affinity

Acknowledgments

Authors are thankful to Professor M. Shakir, Chairman, Department of Chemistry, Aligarh Muslim University, Aligarh (India) for providing necessary facilities for research. Authors are highly indebted to the Punjab University Chandigarh for providing CHN analysis, NMR and ESI-Mass spectra and IIT Guwahati for EPR studies. The author Nausheen Bano is thankful to University Grants Commission (UGC) for financial assistance. The facilities given to the department under SAP-DRS-II, FIST and PURSE programs are highly acknowledged.