Syntheses, urease inhibition activities, and fluorescent properties of transition metal complexes

Abstract

Four transition metal complexes with Schiff base and 1,10-phenanthroline, [Cu(L)(phen)]₂·C₂H₅OH (1), [Zn(L)(phen)]₂·C₂H₅OH (2), [Ni(L)(phen)]₂·C₂H₅OH (3), and [Co(L)(phen)]₂·C₂H₅OH (4) (H₂L = 1-((2-hydroxynaphthalen-1-yl)methylene)thiosemicarbazide; phen = 1,10-phenanthroline) were synthesized and characterized by physico-chemical methods. The crystal structure of 1 was determined by X-ray single-crystal diffraction analysis. 1 crystallizes in the orthorhombic space group Pbca with a = 15.008(9), b = 16.100(10), c = 37.54(2) Å, V = 9070(10) ų, Z = 8, GOOF = 1.002, R ₁ = 0.0626, and wR ₂ = 0.0912. The fluorescence and urease inhibitory activities of the compounds were tested. The enzymatic activity study indicated that 3 possessed potent inhibition against jack bean urease, with IC₅₀ = 1.2 ± 0.1 μM, and about 35 times more than 42.1 ± 0.4 acetohydroxamic acid as positive reference. This suggests that inhibitory efficiency of these complexes can be strongly influenced by different transition metal ions.

Keywords:

• Transition metal complexes
• Mixed ligands
• Fluorescent properties
• Urease inhibition activities

Acknowledgements

This work was financially supported by the NSF of China (21001071, 21271125, 21201116), Foundation for University Key Teacher by Henan Educational Committee (2010GGJS-157), Research Program of Foundation and Advanced Technology of Henan Province (122300410386, 122102210255, 132309410397) and NSF of Henan Educational Committee (2010A150018).