Synthesis and characterization of new isomeric water-soluble porphyrins.  Tetra(2-N-methylpyridyl)porphine and tetra(3-N-methylpyridyl)porphine

Hambright, Peter; Gore, T. S.; Burton, Marilyn.

doi:10.1021/ic50163a072

Cited by 81 publications

(30 citation statements)

References 11 publications

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“…The metal-free ligands were characterized as well, and their UV-visible data, given under "Materials and Methods," agree well with literature data (15). The metalloporphyrins resist strongly acidic (36% HCl) and basic conditions (1 M NaOH).…”

Section: Resultssupporting

confidence: 70%

“…Thus, meso-tetrakis(2-methylphenyl)porphyrin behaves similar to the meso tetramethylporphyrin (14). The same was found for other porphyrins in which meso phenyl groups have different ortho substituents, as well as when meso groups are ortho pyridyls, such as 5,10,15,20-tetrakis-(N-methylpyridinium-2-yl) (H 2 TM-2-PyP 4ϩ ) and its zinc complex, ZnTMP-2-PyP 4ϩ (15)(16)(17)(18)(19). Such a profound impact on the properties of the ortho isomers, known as the ortho effect, is due to the combined effect of inductive, resonance, and steric factors (20,21).…”

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confidence: 68%

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The Ortho Effect Makes Manganese(III)Meso-Tetrakis(N-Methylpyridinium-2-yl)Porphyrin a Powerful and Potentially Useful Superoxide Dismutase Mimic

Batinić‐Haberle¹,

Benov²,

Spasojević³

et al. 1998

Journal of Biological Chemistry

255

300

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The ortho, meta, and para isomers of manganese(III) 5,10,15,20-tetrakis(N-methylpyridyl)porphyrin, MnTM-2-PyP 5؉ , MnTM-3-PyP 5؉, and MnTM-4-PyP 5؉ , respectively, were analyzed in terms of their superoxide dismutase (SOD) activity in vitro and in vivo. The impact of their interaction with DNA and RNA on the SOD activity in vivo and in vitro has also been analyzed. Differences in their behavior are due to the combined steric and electrostatic factors. In vitro catalytic activities are closely related to their redox potentials. The half-wave potentials (E1 ⁄2 ) are ؉0.220 mV, ؉0.052 mV, and ؉0.060 V versus normal hydrogen electrode, whereas the rates of dismutation (k cat ) are 6.0 ؋ 10 7 , 4.1 ؋ 10 6 , and 3.8 ؋ 10 6 M ؊1 s ؊1 for the ortho, meta, and para isomers, respectively. However, the in vitro activity is not a sufficient predictor of in vivo efficacy. The ortho and meta isomers, although of significantly different in vitro SOD activities, have fairly close in vivo SOD efficacy due to their similarly weak interactions with DNA. In contrast, due to a higher degree of interaction with DNA, the para isomer inhibited growth of SOD-deficient Escherichia coli.Due to their high stability and chemical versatility, manganese porphyrins are a promising group of compounds for development as SOD 1 mimics. Introducing ␤-electron-withdrawing substituents and modifying meso substituents of water soluble porphyrins can have a major impact on the redox and electrostatic properties of manganese porphyrins (1-7). Such substitution allows the redox potential to approach the potential of SOD itself, E1 ⁄2 ϳ ϩ0.26 V (8). This is approximately midway between the redox potentials of the two half-reactions of the dismutation process (9, 10). While maintaining the redox potential at a value close to that of SOD, it is important to also ensure electrostatic facilitation. We have already shown that ␤-bromination (11, 12) of the manganese(III) 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrin (13) and of manganese(III) 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin increases their SOD-like activities (13).2 However, the large positive redox potential of the former, E1 ⁄2 ϭ ϩ0.480 mV versus NHE, (13) stabilizes manganese in its 2ϩ state and diminishes stability, and the latter compound had only modest activity, probably due to lack of electrostatic facilitation (13).It has been shown that ortho substitution on the meso phenyl ring exhibits an ortho effect that is as strong as if the same substituent were placed directly on the meso position (14). Thus, meso-tetrakis(2-methylphenyl)porphyrin behaves similar to the meso tetramethylporphyrin (14). The same was found for other porphyrins in which meso phenyl groups have different ortho substituents, as well as when meso groups are ortho pyridyls, such as 5,10,15,20-tetrakis-(N-methylpyridinium-2-yl) (H 2 TM-2-PyP 4ϩ ) and its zinc complex, ZnTMP-2-PyP 4ϩ (15)(16)(17)(18)(19). Such a profound impact on the properties of the ortho isomers, known as the ortho effect, is due to the combi...

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Section: Resultssupporting

confidence: 70%

supporting

confidence: 68%

The Ortho Effect Makes Manganese(III)Meso-Tetrakis(N-Methylpyridinium-2-yl)Porphyrin a Powerful and Potentially Useful Superoxide Dismutase Mimic

Batinić‐Haberle¹,

Benov²,

Spasojević³

et al. 1998

Journal of Biological Chemistry

255

300

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show abstract

“…More details (UV-vis and 1 H NMR spectra data) have been described in our previous work [16]. N-methylated meso-tetra(pyridyl)porphyrins were prepared by refluxing the corresponding porphyrin with excess amounts of methyltosylate in dimethylformamide (DMF) and purified according to the literature [18,22]. H 2 T(2-Mepy)P: 1 …”

Section: Preparation Of Porphyrinsmentioning

confidence: 99%

Stereoelectronic effects of the meso-substituents on the catalytic performance of iron(III) meso-tetraarylporphyrins: Pyridyl and N-methylated pyridyl groups compared to phenyl, 4-methoxyphenyl and 4-sulfonatophenyl ones

Zakavi

Yazdeli

2013

Journal of Molecular Catalysis A: Chemical

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“…The iron(III) derivative of H 2 TMPyP [11] was prepared according to reported methods with a slight modification. The purity of the product was checked by comparison with the known extinction coefficient [12].…”

Section: Synthesismentioning

confidence: 99%

Formation of ferryl porphyrin by electrochemical reduction of iron porphyrin in aqueous solution

Rana¹,

Tamagake²

2005

Journal of Electroanalytical Chemistry

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Synthesis and characterization of new isomeric water-soluble porphyrins. Tetra(2-N-methylpyridyl)porphine and tetra(3-N-methylpyridyl)porphine

Cited by 81 publications

References 11 publications

The Ortho Effect Makes Manganese(III)Meso-Tetrakis(N-Methylpyridinium-2-yl)Porphyrin a Powerful and Potentially Useful Superoxide Dismutase Mimic

The Ortho Effect Makes Manganese(III)Meso-Tetrakis(N-Methylpyridinium-2-yl)Porphyrin a Powerful and Potentially Useful Superoxide Dismutase Mimic

Stereoelectronic effects of the meso-substituents on the catalytic performance of iron(III) meso-tetraarylporphyrins: Pyridyl and N-methylated pyridyl groups compared to phenyl, 4-methoxyphenyl and 4-sulfonatophenyl ones

Formation of ferryl porphyrin by electrochemical reduction of iron porphyrin in aqueous solution

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