A new μ-oxo di-iron complex with suitable features to mimic metallohydrolase activity: X-ray molecular structure, aqua solution behavior and nuclease activity of the complex [Fe(HPClNOL)(SO4)]2-μ-oxo

The reaction of FeSO4 · 7H2O with the ligand HPClNOL (1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol results in the complex [Fe(HPClNOL)(SO4)]2-μ-oxo · 6H2O 1, in which the iron ions are coordinated by two pyridines, one amine and one alcohol group from the ligand HPClNOL, an oxo bridge and monodentate sulfate ion. The complex is highly soluble in water and potentiometric titration experiments reveal four protonation/deprotonation equilibria, with pKa values of 2.77(3), 4.34(6), 8.07(4) and 8.58(8). The nuclease activity of complex 1 was evaluated at pH 7.0, 8.0 and 9.0. Complex 1 was able to promote single and double strand DNA cleavage in both aerobic and anaerobic condition, indicating that the cleavage process should follow a hydrolytic mechanism.

Graphical abstractComplex [Fe(HPClNOL)(SO4)]2-μ-oxo successfully promotes the hydrolytic cleavage of plasmid DNA, producing single and double DNA strand breaks at very low concentrations and at physiological pH.Figure optionsDownload full-size imageDownload as PowerPoint slide