title: Heme cleavage with remarkable ease: paramagnetic intermediates formed by aerobic oxidation of a meso-amino-substituted iron porphyrin.
abstract: Hemes must be oxidatively stable to carry out their functions as biological oxidants, but introduction of a single amino group at a meso position of octaethylheme renders it extremely sensitive to ring opening by dioxygen. Exposure of a red pyridine (py) solution of diamagnetic (py)(2)Fe(II)(H(2)N-OEP) (1) (H(2)N-OEP is the dianion of meso-amino-octaethylporphyrin) to air results in the immediate formation of a green intermediate which is subsequently converted into a second species that has been crystallized and characterized by X-ray diffraction. This process is distinct from coupled oxidation, a model for biological heme cleavage, because it does not require a sacrificial reducing agent to initiate the process.
authors.affiliation: Department of Chemistry, University of California - Davis, One Shields Avenue, Davis, California 95616, USA.
authors.forename: Heather
authors.initials: H
authors.lastname: Kalish
authors.forename: Hon Man
authors.initials: HM
authors.lastname: Lee
authors.forename: Marilyn M
authors.initials: MM
authors.lastname: Olmstead
authors.forename: Lechosław
authors.initials: L
authors.lastname: Latos-Grazyński
authors.forename: Sankar Prasad
authors.initials: SP
authors.lastname: Rath
authors.forename: Alan L
authors.initials: AL
authors.lastname: Balch
mesh_terms: D006418:Heme / Q000737:chemistry* / Q000378:metabolism; D058085:Iron Compounds / Q000737:chemistry; D008968:Molecular Conformation; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D011166:Porphyrins / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D058085:Iron Compounds; D011166:Porphyrins; D006418:Heme