Hybrid Organic-Inorganic Copper and Cobalt Complexes for Antimicrobial Potential Applications

The naturally occurring phenolic chemical curcumin (CUR), which was derived from the Curcuma longa plant, has a variety of biological actions, including anti-inflammatory, antimicrobial, antioxidant, and anticancer activities. Curcumin is known for its restricted bioavailability due to its hydrophobicity, poor intestinal absorption, and quick metabolism. To boost the biological effects of these bioactive molecules, it is necessary to raise both their bioavailability and their solubility in water. Aim: The aim of this study is to synthesize and characterize hybrid organic-inorganic complexes of copper and cobalt, and to evaluate their antimicrobial potential against a range of pathogenic microorganisms.

The synthesis of metal curcumin complexes (Cu-CUR and Co-CUR) was achieved by mixing curcumin with copper acetate monohydrate. The solid residue was isolated, filtered, and dried in an oven. X-ray diffraction analysis was used to identify the structure and phase of the prepared samples. FTIR spectra were recorded using a Shimadzu 2200 module. The antimicrobial activity of the prepared complexes was evaluated against four bacterial strains and two Candida species. The chemical materials were dissolved in DMSO to a final concentration of 20%, and the plates were incubated at 37°C for 24 hours. The results showed that the prepared complexes had antimicrobial activity against the tested microorganisms.

The study compared the Powder X-ray diffraction (XRD) patterns of prepared copper and cobalt complexes to pure curcumin, revealing new, isostructural complexes. The FTIR analysis showed that the Cu-CUR and Co-CUR complexes varied in their inhibitory effect against microorganisms, with Co-CUR being more effective. The results are consistent with previous studies showing the cobalt-curcumin complex was effective against various bacterial genera, with inhibition activity varying depending on the species and strains of microorganisms.

Copper and cobalt curcumin complexes, synthesized at room temperature, exhibit high crystallinity and antimicrobial activity. Co-CUR, with its superior antibacterial potential, outperforms pure curcumin in inhibiting microbes. Further investigation is needed to understand their interaction mechanisms with bacteria and fungi.