Structural Characterization and Bioactivity of a Titanium(IV)-Oxo Complex Stabilized by Mandelate Ligands

Molecules. 2024 Apr 11;29(8):1736. doi: 10.3390/molecules29081736.

Abstract

Research on titanium-oxo complexes (TOCs) is usually focused on their structure and photocatalytic properties. Findings from these investigations further sparked our interest in exploring their potential biological activities. In this study, we focused on the synthesis and structure of a compound with the general formula [Ti8O2(OiPr)20(man)4] (1), which was isolated from the reaction mixture of titanium(IV) isopropoxide with mandelic acid (Hman) in a molar ratio of 4:1. The structure (1) was determined using single-crystal X-ray diffraction, while spectroscopic studies provided insights into its physicochemical properties. To assess the potential practical applications of (1), its microcrystals were incorporated into a polymethyl methacrylate (PMMA) matrix, yielding composite materials of the type PMMA + (1) (2 wt.%, 5 wt.%, 10 wt.%, and 20 wt.%). The next stage of our research involved the evaluation of the antimicrobial activity of the obtained materials. The investigations performed demonstrated the antimicrobial activity of pure (1) and its composites (PMMA + (1)) against both Gram-positive and Gram-negative strains. Furthermore, MTT tests conducted on the L929 murine fibroblast cell line confirmed the lack of cytotoxicity of these composites. Our study identified (1) as a promising antimicrobial agent, which is also may be use for producing composite coatings.

Keywords: antimicrobial activity; crystal structure; cytotoxicity; mandelic acid; titanium(IV)-oxo complex; α-hydroxyacid.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Cell Line
  • Coordination Complexes / chemical synthesis
  • Coordination Complexes / chemistry
  • Coordination Complexes / pharmacology
  • Crystallography, X-Ray
  • Fibroblasts / drug effects
  • Ligands
  • Mandelic Acids / chemistry
  • Mandelic Acids / pharmacology
  • Mice
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Titanium* / chemistry
  • Titanium* / pharmacology

Substances

  • Titanium
  • Ligands
  • Mandelic Acids
  • Anti-Bacterial Agents
  • mandelic acid
  • Coordination Complexes

Grants and funding

The studies have been carried out within the Project 4101.00000085 IDUB/IDUB Biomaterials and Cosmetics Research Group, Nicolaus Copernicus University in Toruń, Poland.