An Investigation on the Pharmacological Profile of Titanium (IV) and Aluminum (III) 8-Hydroxyquinoline Derivatives Grafted on MCM-41 Mesoporous Silica

Abstract

Introduction: Regarding the increasing applications of nanomedicine in clinical practice, we aimed to assess the antibacterial and anti-fungal effects of nanocomposite complexes of titanium (IV) and aluminum (III). Methods: 8-hydroxyquinoline and 5-chloro-8-hydroxyquinoline were treated with titanium (IV) and Aluminum (III) alkoxide reagents to generate (Q)2 (2-BuO) Al (Q = 8-hydroxyquinoline and 5-chloro-8-hydroxyquinoline) and (Q)2 (O-i Pr)2 Ti (Q = 5-chloro-8-hydroxyquinoline) complexes. These active complexes were grafted on MCM-41 mesoporous silica in order to improve the overall toxicity and stability of them. Anti-bacterial and anti-fungal activities of the compounds were assessed. Results: The prepared materials were stable both under air and high temperature (at least up to 200°C). These nanocomposites were well dispersed in water. It was observed that (Q-Cl)2Ti@MCM-41 nanocomposite had anti-bacterial activity against Staphylococcus aureus at concentrations of 50, 75 and 120 ppm while at the 75, and 120 ppm concentrations against Escherichia coli and Salmonella typhi. The Q2Al@MCM-41 weakly inhibited the bacterial growth of E. coli at 75 and 120 ppm concentrations. (Q-Cl)2Al@MCM-41 did not show any antibacterial activity at any concentration. Moreover, (Q-Cl)2Ti@MCM-41 and (Q-Cl)2Al@MCM41 showed considerable anti-fungal activity against Saccharomyces cerevisiae at 50, 75, 120, and 150 ppm concentrations. The nanoparticles partly inhibited the growth of Kluyveromyces marxianus and Macrophomina phaseolina fungi at 150 ppm concentration. Conclusion: The results showed that the anti-microbial (bacterium and fungi) effect of the titanium and aluminum nanocomposite complexes can be improved in the solid state using appropriate chlorine substituent on the 8-hydroxyquinoline ligand and grafting to the mesoporous silica.

Keywords

• MCM-41
• Titanium
• Aluminum
• 8-hydroxyquinoline
• Anti-bacterial activity
• anti-fungal activity