Synthesis and characterization of ligational behavior of curcumin drug towards some transition metal ions: Chelation effect on their thermal stability and biological activity

Complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with curcumin ligand as antitumor activity were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV–Vis, IR, Raman, ESR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a monobasic bidentate ligand towards the central metal ion with an oxygen’s donor atoms sequence of both OH and CO groups under keto–enol structure. From the microanalytical data, the stoichiometry of the complexes 1:2 (metal:ligand) was found. The ligand and their metal complexes were screened for antibacterial activity against Escherichia Coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa and fungicidal activity against Aspergillus flavus and Candida albicans.

Graphical abstractInhabitation zone diameter of curcumin complexes towards some kind of bacteria and fungi.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The novel Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of curcumin have synthesized. ► The prepared complexes play an important role in many biological systems. ► Curcumin is capable of existing in tautomeric forms. ► The Zn(II) complex has crystalline particles in nano scale range.