Co(II), Ni(II), and Zn(II) complexes of 5-methyl-1,3,4-oxadiazol-2-amine Schiff base as potential heat shock protein 90 inhibitors: Spectroscopic, biological activity, density functional theory, and molecular docking studies

Heat shock protein 90 (Hsp90) is a promising target in tumor biology as required for oncogenic protein kinases. The Hsp90-alpha N-domain delineates an ATP binding pocket; therefore, the ligands competitors to ATP are potential Hsp90 inhibitors. This study demonstrates the inhibition of the N-terminal ATPase of Hsp90 with 4-methyl-2-(((5-methyl-1,3,4-oxadiazol-2-yl)amino)methyl)phenol (MoxOH) and their Co(II), Ni(II), and Zn(II) complexes. MoxOH and its complexes were successfully synthesized and characterized using Fourier transform infrared (FT-IR), UV-visible, mass spectroscopy, H-1 and C-13 nuclear magnetic resonance (NMR), and magnetic and conductivity measurements. By employing density functional theory B3LYP/LANL2DZ+6-31+G(d,p) as a basis set, we have examined their spectral and structural properties, such as the energy band gap, dipole moment, chemical potential, Mulliken charge distributions, and highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) interactions. The activity of the compounds against Hsp90 has been investigated using molecular docking. They showed excellent binding percentages of up to 100% to the ATP binding pocket and low binding energies ranging from -7.2 to -9.5 kcal mol(-1). The antibacterial properties of these compounds made them effective against Gram-positive and Gram-negative bacteria. These compounds were highly effective at inhibiting the growth of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. These complexes may offer new hope for cancer therapy and take the metallodrugs field to new heights.