Fluorescence Spectral Study on the Interaction Between Copper(II) Complex with (E)-3-(2,3-Dihydrobenzo[b][1,4] Dioxin-6-Yl) Acrylic Acid and Urease

We have previously reported the synthesis, structure and urease inhibitory activity of a complex [Cu-2(L)(4)DMSO2] 2DMSO (HL = (E)-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)acrylic acid), and we found the complex to show a strong inhibitory activity against jack bean urease [1]. In this study, the interaction of the complex and urease is studied by fluorescence spectroscopy. We find that the fluorescence quenching mechanism of the complex with urease is static quenching. The quenching rate constant (K-q) is 1.6 10(12) l/mol s( -1), the quenching constant (K-sv) is 1.6x10(4) l/mol, the association binding constant (K) is 3.55 10(4) l/mol, and the binding site number (n) is 1.22.