Heme cleavage with remarkable ease: paramagnetic intermediates formed by aerobic oxidation of a meso-amino-substituted iron porphyrin.
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.
Kalish
Heather
H
Department of Chemistry, University of California - Davis, One Shields Avenue, Davis, California 95616, USA.
Lee
Hon Man
HM
Olmstead
Marilyn M
MM
Latos-Grazyński
Lechosław
L
Rath
Sankar Prasad
SP
Balch
Alan L
AL
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
D058085:Iron Compounds; D011166:Porphyrins; D006418:Heme