Engineered for impact: Multifunctional Co(II), Ni(II), Cu(II), and Cd(II) complexes of 2-aminobenzothiazole with potent antitumor, antibacterial, and antioxidant actions supported by theoretical approaches

Abstract

We synthesized and analyzed four novel Co(II), Ni(II), Cu(II), and Cd(II) complexes utilizing a Schiff base ligand (L) derived from 4‑chloro-2-oxo-2H-chromene-3-carbaldehyde and 2-Aminobenzothiazole. Herein, the structural compositions of these compounds were elucidated through analytical and spectroscopic techniques, including IR, ^1HNMR , ^13CNMR , mass spectrometry, electronic spectra, PXRD, and thermal analysis. Based on physical and chemical, and theoretical studies, the general formula [ML(H₂O)Cl₂]·2H₂O was proposed, molecular modeling confirms that the complexes have an octahedral geometry. PXRD analysis demonstrated that the crystallite size of the synthesized compounds ranged between 20.97 and 49.56 nm. The complexes' biological activities were measured for their antibacterial, antitumor, and antioxidant properties utilizing cisplatin, ampicillin, gentamicin, and ascorbic acid as reference standards. The activity followed the sequence: [CuL(H₂O)Cl₂]·2H₂O>[NiL(H₂O)Cl₂]·2H₂O>[CoL(H₂O)Cl₂]·2H₂O>[CdL(H₂O)Cl₂]·2H₂O>L. Molecular docking studies, conducted using MOA2022 software, assessed the binding potential of these complexes by the active sites of Bacillus subtilis receptor (PDB ID: 5E6K) and methionine adenosyl-transferases in liver tumor (PDB ID: 5A19), breast cancer MCF-7 human (PDB ID: 4zvm). The binding strength correlated with increasingly negative binding energy, following the trend: L˂[CdL(H₂O)Cl₂]˂[CoL(H₂O)Cl₂]˂[NiL(H₂O)Cl₂]˂ [CuL(H₂O)Cl₂], suggesting that the Cu(II) complex exhibited the highest binding affinity and potential biological activity.