Synthesis, crystal structure, spectroscopic, and biological studies on Cu(II) complexes of N,O donor dimethyl isoxazole Schiff bases

Abstract

Cu(II) complexes with Schiff bases DMIIMP, DMIIMBD, DMIIMBP, DMIIMCP, DMIIMMP, and DMIIMNP (see Introduction for definitions) are derived from condensation of 3,4-dimethyl 5-amino-isoxazole with salicylaldehyde and substituted salicylaldehydes. The newly synthesized ligands were characterized by IR, UV-Vis, 1 H NMR, 13 C NMR, mass spectra, and elemental analysis. The Cu(II) complexes were characterized by IR, UV-Vis, ESR, elemental analysis, magnetic moments, thermogram, DTA, and single crystal analysis. The complexes have general formula [M (L) 2 ]. The Schiff bases are bidentate coordinating through the azomethine nitrogen and phenolic oxygen of salicylaldehydes. Based on the analytical and spectral data, four-coordinate geometry is assigned for all the complexes. ESR and single crystal analysis suggests square planar geometry for all complexes. [Cu(DMIIMP) 2 ] crystallizes in the orthorhombic system. Antimicrobial studies of Schiff bases and their metal complexes show significant activity with the metal complexes showing more activity than corresponding Schiff bases. Cytotoxicity of the copper complexes on human cervical carcinoma cells (HeLa) was measured using the Methyl Thiazole Tetrazolium assay.

DNA Cleavage, Cytotoxic Activities, and Antimicrobial Studies of Ternary Copper(II) Complexes of Isoxazole Schiff Base and Heterocyclic Compounds

“…The physical and spectral data, such as IR, mass, 1 H-NMR, and 13 C-NMR, obtained for these ligands were in good agreement with the literature data [22]. …”

“…The two ligands DMIIMBP and DMIIMCP reported earlier were yellow in colour and stable to air and moisture. The physical and spectral data, such as IR, mass, 1 H-NMR, and 13 C-NMR, obtained for these ligands were in good agreement with the literature data [ 22 ].…”

“…Briefly, the copper complexes ( 1 , 2 , 5 , and 6 ) were dissolved in DMSO, diluted in culture medium, and used to treat the cancer cell, with the complex in the concentration range of 2 to 10 μ g/mL, for a period of 72 h. DMSO diluted in the culture medium was used as the solvent control. A miniaturized viability assay using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) was carried out according to the method described earlier [ 22 ]. HeLa cells growing exponentially were added to 96-well plates (Orange Scientific) at a density of 3 x 103 per well after counting on Bright Line Haemocytometer (Sigma Ltd.).…”

Mono and dinuclear copper(II) naproxenato complexes containing 3-picoline and 4-picoline: synthesis, structure, properties, catechol oxidase, and antimicrobial activities

“…Antimicrobial activities of the complexes were higher than the drug molecules in the absence of copper. These results have good agreement with similar studies available in the literature [64][65][66][67].…”