The autoxidation of 3-hydroxyanthranilic acid

Manthey, Michael K.; Pyne, Stephen G.; Truscott, Roger J.W.

doi:10.1021/jo00242a026

Cited by 25 publications

(6 citation statements)

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“…The identification of CA as the oxidation product through different processes had already been studied. [33][34][35] We confirmed that the main product of 3-HAA oxidation by laccase is CA by comparison of the UV/Vis scan with data reported by Eggert et al [2] and by mass spectrometry analysis (APCI, positive mode), which showed the expected peak [M + H] at 301 m/z, in accordance with previous literature results. [2,3,32] Analysis of 3-HOA biotransformation media required an appropriate method to be set up.…”

Section: Biotransformation Of 3-haa and 3-hoa By Use Of Fungal Laccassupporting

confidence: 91%

Regioselective Synthesis of 3‐Hydroxyorthanilic Acid and Its Biotransformation into a Novel Phenoxazinone Dye by Use of Laccase

Bruyneel¹,

Enaud²,

Billottet³

et al. 2007

Eur J Org Chem

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A natural phenoxazinone derivative, cinnabarinic acid (2, CA, R = CO2H), could be obtained in vitro with the aid of purified laccase from the fungi Pycnoporus cinnabarinus by oxidative dimerization of 3‐hydroxyanthranilic acid (1, 3‐HAA, R = CO2H). With the aim of gaining access to a new class of water‐soluble chromophores and potential bioactive molecules, the regioselective sulfonation of 2‐hydroxyaniline was investigated. Straightforward insertion of a sulfonate group into a carbon–metal bond provided an efficient and selective process for the synthesis of 3‐hydroxyorthanilic acid (3, 3‐HOA, R = SO3H). This sulfonated compound was then subjected to laccase oxidation in order to mimic the cinnabarinic acid synthesis. A practical HPLC method to study the oxidized products was developed, and the major product of biotransformation – namely 2‐amino‐3‐oxo‐3H‐phenoxazin‐1,9‐disulfonic acid (4, LAO, R = SO3H) – was isolated and identified as the sulfonate analogue of cinnabarinic acid.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

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Section: Biotransformation Of 3-haa and 3-hoa By Use Of Fungal Laccassupporting

confidence: 91%

Regioselective Synthesis of 3‐Hydroxyorthanilic Acid and Its Biotransformation into a Novel Phenoxazinone Dye by Use of Laccase

Bruyneel¹,

Enaud²,

Billottet³

et al. 2007

Eur J Org Chem

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“…Previous studies on the autoxidation of 3-hydroxyanthralinic acid, a structural analogue of 3-OHKyn, revealed that H202 plays an important role in the generation of specific autoxidation products, ngI In particular, cinnabarinic acid, a phenoxazone dimer of 3-hydroxyanthranilinic acid and structural analogue of Xan, was degraded by H202 . [19] As noted above, we suspected that a similar reaction may also occur with Xan. This hypothesis was tested by performing the autoxidation of 3-OHKyn at pH 7 in the presence of catalase to remove H202 (produced during the course of autoxidation).…”

Section: Generation Of Hydrogen Peroxide During 3-hydroxykynurenine Amentioning

confidence: 68%

Characterisation of the major autoxidation products of 3-hydroxykynurenine under physiological conditions

Vázquez

Garner

Sheil

et al. 2000

Free Radical Research

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3-Hydroxykynurenine (3-OHKyn) is a tryptophan metabolite that is readily autoxidised to products that may be involved in protein modification and cytotoxicity. The oxidation of 3-OHKyn has been studied here with a view to characterising the major products as well as determining their relative rates of formation and the role that H2O2 and hydroxyl radical (HO*) may play in modifying the autoxidation process. Oxidation of 3-OHKyn generated several compounds. Xanthommatin (Xan), formed by the oxidative dimerisation of 3-OHKyn, was the major product formed initially. It was, however, found to be unstable, particularly in the presence of H2O2, and degraded to other products including the p-quinone, 4,6-dihydroxyquinolinequinonecarboxylic acid (DHQCA). A compound that has a structure consistent with that of hydroxyxanthommatin (OHXan) was also formed in addition to at least two minor species that we were unable to identify. Hydrogen peroxide was formed rapidly upon oxidation of 3-OHKyn, and significantly influenced the relative abundance of the different autoxidation species. Increasing either pH (from pH 6 to 8) or temperature (from 25 degrees C to 35 degrees C) accelerated the rate of autoxidation but had little impact on the relative abundance of the autoxidation species. Using electron paramagnetic resonance (EPR) spectroscopy, a clear phenoxyl radical signal was observed during 3-OHKyn autoxidation and this was attributed to xanthommatin radical (Xan*). Hydroxyl radicals were also produced during 3-OHKyn autoxidation. The HO* EPR signal disappeared and the Xan* EPR signal increased when catalase was added to the autoxidation mixture. The HO* did not appear to play a role in the formation of the autoxidation products as evidenced using HO* traps/scavengers. We propose that the cytotoxicity of 3-OHKyn may be explained by both the generation of H2O2 and by the formation of reactive 3-OHKyn autoxidation products such as the Xan* and DHQCA.

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“…The fact that inclusion of SOD and xanthine/xanthine oxidase into the reaction mixture resulted in increased and decreased formation of CA, respectively (Figure 2), indicates that O2* ™ is formed during and participates to some extent in the peroxyl radical-induced conversion of 3HAA into CA. Univalent reduction of molecular oxygen to O2• ™ has been proposed to be associated with the initial formation of the anthranilyl radical (1) as a result of autoxidation of 3HAA (Dykens et al, 1987;Manthey et al, 1988). As this reaction is of minor importance under our conditions (Figure IB), it is more likely that reaction of 1 (Dykens et al, 1987;Manthey et al, 1988) or proposed subsequent intermediates (4 or 7) reduces molecular oxygen to O2•~(Scheme II).…”

Section: Discussionmentioning

confidence: 83%

“…Univalent reduction of molecular oxygen to O2• ™ has been proposed to be associated with the initial formation of the anthranilyl radical (1) as a result of autoxidation of 3HAA (Dykens et al, 1987;Manthey et al, 1988). As this reaction is of minor importance under our conditions (Figure IB), it is more likely that reaction of 1 (Dykens et al, 1987;Manthey et al, 1988) or proposed subsequent intermediates (4 or 7) reduces molecular oxygen to O2•~(Scheme II). In analogy with the chromanoxyl radical (Cadenas et al, 1989) a reduction of 1 to 3HAA by €>2* ~may explain the observed stimulatory effect of SOD on consumption of 3HAA (Figure 2A, Scheme II).…”

Section: Discussionmentioning

confidence: 83%

Oxidation of 3-hydroxyanthranilic acid to the phenoxazinone cinnabarinic acid by peroxyl radicals and by compound I of peroxidases or catalase

Christen¹,

Southwell-Keely²,

Stocker³

1992

Biochemistry

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Since 3-hydroxyanthranilic acid (3HAA), an oxidation product of tryptophan metabolism, is a powerful radical scavenger [Christen, S., Peterhans, E., & Stocker, R. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 2506], its reaction with peroxyl radicals was investigated further. Exposure to aqueous peroxyl radicals generated at constant rate under air from the thermolabile radical initiator 2,2'-azobis[2-amid-inopropane] hydrochloride (AAPH) resulted in rapid consumption of 3HAA with initial accumulation of its cyclic dimer, cinnabarinic acid (CA). The initial rate of formation of the phenoxazinone CA accounted for approximately 75% of the initial rate of oxidation of 3HAA, taking into account that 2 mol of 3HAA are required to form 1 mol of CA. Consumption of 3HAA under anaerobic conditions (where alkyl radicals are produced from AAPH) was considerably slower and did not result in detectable formation of CA. Addition of superoxide dismutase enhanced autoxidation of 3HAA as well as the initial rates of peroxyl radical-induced oxidation of 3HAA and formation of CA by approximately 40-50%, whereas inclusion of xanthine/xanthine oxidase decreased the rate of oxidation of 3HAA by approximately 50% and inhibited formation of CA almost completely, suggesting that superoxide anion radical (O2.-) was formed and reacted with reaction intermediate(s) to curtail formation of CA. Formation of CA was also observed when 3HAA was added to performed compound I of horseradish peroxidase (HRPO) or catalytic amounts of either HRPO, myeloperoxidase, or bovine liver catalase together with glucose/glucose oxidase.(ABSTRACT TRUNCATED AT 250 WORDS)

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The autoxidation of 3-hydroxyanthranilic acid

Cited by 25 publications

References 0 publications

Regioselective Synthesis of 3‐Hydroxyorthanilic Acid and Its Biotransformation into a Novel Phenoxazinone Dye by Use of Laccase

Regioselective Synthesis of 3‐Hydroxyorthanilic Acid and Its Biotransformation into a Novel Phenoxazinone Dye by Use of Laccase

Characterisation of the major autoxidation products of 3-hydroxykynurenine under physiological conditions

Oxidation of 3-hydroxyanthranilic acid to the phenoxazinone cinnabarinic acid by peroxyl radicals and by compound I of peroxidases or catalase

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