Structural investigations and antibacterial, antifungal and anticancer studies on zinc salicylaldimine complexes

Abstract

Aim: Zinc salicylaldimines may act as multidrug agents. Results: Three zinc salicylaldimines C1–C3 and respective ligands HL¹–HL³ were examined for antimicrobial/anticancer drug action and C3 was structurally analyzed (tetrahedral, triclinic). Against two fungi, C1 inhibited Candida albicans with 12 mm (21 mm for amphotericin B). Among four bacteria, two ligands inhibited Staphylococcus aureus and Escherichia coli (9–10 mm), but the complexes inhibited all bacteria with 10–14 mm (21–26 mm for ampicillin). The half-maximal inhibitory concentrations for the ligands, complexes and doxorubicin were 195.5–310.7, 22.18–70.05 and 9.66 μM against cancerous MCF-7 cells and 186.4–199.9, 14.95–18.87 and 36.42 μM against normal BHK cells. Conclusion: The complexation produced pronounced enhancement in the ligand antimicrobial/anticancer activities, despite these activities are moderate comparing with standards.

Article highlights

Experimental

• Three zinc complexes with the salicylaldimine ligands 2-(-(2,4-dimethylphenylimino)methyl)phenol (HL¹), 2-(-(2,5-dimethylphenylimino)methyl)phenol (HL²) and 2-(-(3,4-dimethylphenylimino)methyl)phenol (HL³) were introduced.

Results & discussion

• The exact structural data for complex C3 were determined.

• All complexes and ligands were tested for antibacterial (against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa), antifungal (against Candida albicans and Aspergillus flavus) and anticancer effects (against MCF-7 cancer cells, whereas normal BHK cells were used to test selectivity against cancer cells).

• Against the microbes and MCF-7 cells, pronounced enhancement in the activities of ligands was detected after complexation.

• The standards ampicillin, amphotericin B and doxorubicin were used and their activities are greater comparing with those of the complexes.

Keywords: :

• anionic ligands
• breast
• diamagnetism
• doxorubicin
• kidney
• N and O chelation

Author contributions

All authors contributed equally in this research.

Financial disclosure

The authors have no financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Competing interests disclosure

The authors have no competing interests or relevant affiliations with any organization or entity with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Writing disclosure

No writing assistance was utilized in the production of this manuscript.

Data availability statement

Research data are available from the corresponding author upon a reasonable request.