Design of more powerful iron-TAML peroxidase enzyme mimics.
Environmentally useful, small molecule mimics of the peroxidase enzymes must exhibit very high reactivity in water near neutral pH. Here we describe the design and structural and kinetic characterization of a second generation of iron(III)-TAML activators with unprecedented peroxidase-mimicking abilities. Iterative design has been used to remove the fluorine that led to the best performers in first-generation iron-TAMLs. The result is a superior catalyst that meets a green chemistry objective by being comprised exclusively of biochemically common elements. The rate constants for bleaching at pH 7, 9, and 11 of the model substrate, Orange II, shows that the new Fe(III)-TAML has the fastest reactivity at pH's closer to neutral of any TAML activator to date. Under appropriate conditions, the new catalyst can decolorize Orange II without loss of activity for at least 10 half-lives, attesting to its exceptional properties as an oxidizing enzyme mimic.
Ellis
W Chadwick
WC
Institute for Green Science, Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Tran
Camly T
CT
Denardo
Matthew A
MA
Fischer
Andreas
A
Ryabov
Alexander D
AD
Collins
Terrence J
TJ
D001391:Azo Compounds / Q000737:chemistry; D001557:Benzenesulfonates / Q000737:chemistry; D032701:Biomimetics; D002384:Catalysis; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D058085:Iron Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification
D001391:Azo Compounds; D001557:Benzenesulfonates; D058085:Iron Compounds; D047028:Macrocyclic Compounds; D014874:Water Pollutants, Chemical; C517362:iron-3,3,6,6,9,9-hexamethyl-3,4,8,9-tetrahydro-1H-1,4,8,11-benzotetraazacyclotridecine-2,5,7,10(6H,11H)-tetraone; D006861:Hydrogen Peroxide; D009195:Peroxidase; C014722:2-naphthol orange