Generation of FeIIIOEP-hydrogen peroxide complex (OEP = octaethylporphyrinato) by reduction of FeIIOEP–O2with ascorbic acid sodium salt

Tajima, Kunihiko; Shigematsu, Masayuki; Jinno, Junichi; Ishizu, Kazuhiko; Ohya-Nishiguchi, Hiroaki

doi:10.1039/c39900000144

Cited by 39 publications

(30 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…9 It also exhibited an EPR spectrum (77 K) indicative of a low-spin ferric complex with anomalously small g anisotropy. The peroxide complexes Fe 3+ -OEP(OOH) 212 and Fe 3+ "TMP(OOH) 213 were also reported. The EPR spectra of these peroxide complexes contrasted with those of the high-spin ferric peroxo porphyrin complexes discussed earlier and were consistent with those of Fe m (hemoglobin)(OOH) and Fe'"(horseradish peroxidase)(OOH).…”

Section: Heme and Pseudo-heme Iron Dioxygen Complexesmentioning

confidence: 93%

Biomimetic Oxygenations Related to Cytochrome P450: Metal-Oxo and Metal-Peroxo Intermediates

McLain

Lee

Groves

2000

Biomimetic Oxidations Catalyzed by Transition Metal Complexes

123

View full text Add to dashboard Cite

Oxometalloporphyrin Intermediates in Enzymatic ProcessesMetalloenzymes catalyze a host of biological oxidation reactions that are crucial to life processes. The cytochromes P450, an important family of heme-iron metalloenzymes, are oxidoreductases that activate molecular oxygen (O2) and incorporate one of the oxygen atoms into a wide variety of biological substrates, with concurrent two-electron reduction of the other oxygen atom to H 2 0.' The structure, biochemistry, molecular biology and the chemistry of cytochrome P450 and related model systems was extensively reviewed recently. 1 Cytochrome P450 enzymes have been isolated from numerous mammalian tissues (e.g. liver, kidney, lung, intestine and adrenal cortex), as well as insects, plants, yeast and bacteria, 2 and are known to catalyze hydroxylations, epoxidations, N-, S-and O-dealkylations, N-oxidations, sulfoxidations, and dehalogenations. 1 These oxygenation reactions play a central role in carcinogen activation, drug and xenobiotic detoxification, and steroid and prostaglandin metabolism. Surprisingly, the active site of the enzyme, known in detail from several X-ray crystal structures, is extraordinarily simple, with an iron protoporphyrin IX (3.1; Fig. 3.1) buried deep in a hydrophobic, substrate-binding pocket of 91 Biomimetic Oxidations Catalyzed by Transition Metal Complexes Downloaded from www.worldscientific.com by KAINAN UNIVERSITY on 02/20/15. For personal use only.

show abstract

Section: Heme and Pseudo-heme Iron Dioxygen Complexesmentioning

confidence: 93%

Biomimetic Oxygenations Related to Cytochrome P450: Metal-Oxo and Metal-Peroxo Intermediates

McLain

Lee

Groves

2000

Biomimetic Oxidations Catalyzed by Transition Metal Complexes

123

View full text Add to dashboard Cite

show abstract

“…These studies were able to show that the observed species were five-coordinate and high-spin on the basis of their electronic absorption, EPR, and 1 H NMR spectra [50][51][52]. Compounds 18a-19 ( Figure 8) were the first six-coordinate examples [53][54][55] and differed from their five-coordinate counterparts insofar as they displayed EPR spectra characterized by a low g dispersion, consistent with a low-spin Fe(III) center and similar to spectra reported for hydroperoxo (alkylperoxo) adducts of hemoglobin, horseradish peroxidase, and bleomycin [56][57][58].…”

Section: Fe(iii)-hydroperoxo (Alkylperoxo) Intermediatesmentioning

confidence: 97%

“…These reactions are often performed under basic conditions to generate ROO À to yield either a fiveor six-coordinate product. It has also been demonstrated that reduction of an Fe(II)-superoxide followed by protonation can yield a hydroperoxide intermediate, although these examples are rare [23,54].…”

Section: Fe(iii)-hydroperoxo (Alkylperoxo) Intermediatesmentioning

confidence: 97%

Transition Metal Complexes and the Activation of Dioxygen

Yee

Tolman

2014

Metal Ions in Life Sciences

View full text Add to dashboard Cite

In order to address how diverse metalloprotein active sites, in particular those containing iron and copper, guide O₂binding and activation processes to perform diverse functions, studies of synthetic models of the active sites have been performed. These studies have led to deep, fundamental chemical insights into how O₂coordinates to mono- and multinuclear Fe and Cu centers and is reduced to superoxo, peroxo, hydroperoxo, and, after O-O bond scission, oxo species relevant to proposed intermediates in catalysis. Recent advances in understanding the various factors that influence the course of O₂activation by Fe and Cu complexes are surveyed, with an emphasis on evaluating the structure, bonding, and reactivity of intermediates involved. The discussion is guided by an overarching mechanistic paradigm, with differences in detail due to the involvement of disparate metal ions, nuclearities, geometries, and supporting ligands providing a rich tapestry of reaction pathways by which O₂is activated at Fe and Cu sites.

show abstract

“…In the catalytic oxidation cycle of cytochrome P450, one of the essential steps is protonation of an Fe(III) dianion complex to give an Fe-OOH complex and cleavage of the O-O bond to give a reactive ironoxo species [6]. However, investigation of these M-OOH porphyrins have been limited, due to instability of the species, although unstable iron porphyrins bearing an OOH group have been investigated at very low temperatures [24,25].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and properties of group 15 element porphyrin peroxides

Satoh

Masumoto

Yamamoto

et al. 2001

Heteroatom Chemistry

View full text Add to dashboard Cite

show abstract

Generation of Fe^IIIOEP-hydrogen peroxide complex (OEP = octaethylporphyrinato) by reduction of Fe^IIOEP–O₂with ascorbic acid sodium salt

Abstract: ESR and optical absorption spectra have been recorded for a frozen dimethylformamide (DMF) solution of the complex FelllOEP( -OH)( -0OH) (OEP = octaethylporphyrinato) prepared by mixing Fel1OEP(pyridine)-O2 with ascorbic acid sodium salt.

Cited by 39 publications

References 4 publications

Biomimetic Oxygenations Related to Cytochrome P450: Metal-Oxo and Metal-Peroxo Intermediates

Biomimetic Oxygenations Related to Cytochrome P450: Metal-Oxo and Metal-Peroxo Intermediates

Transition Metal Complexes and the Activation of Dioxygen

Synthesis and properties of group 15 element porphyrin peroxides

Contact Info

Product

Resources

About