Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2
|
| pubmed:dateCreated |
1987-3-5
|
| pubmed:abstractText |
The oxidative reactivities of four tryptophan metabolites in the kynurenine pathway were examined as a potential mechanism for their reported neurotoxicities and carcinogenicities. Neither quinolinic acid, a neurotoxin, nor its monocarboxylic analogue, picolinic acid, auto-oxidized over a wide pH range. However, 3-hydroxyanthranilic acid (3-HAT), a carcinogen, readily auto-oxidized and the reaction rate increased exponentially with increasing pH. 3-HAT auto-oxidation likely involves two steps: auto-oxidation of 3-HAT to the semiquinoneimine (anthranilyl radical) which oxidizes to the quinoneimine, followed by condensation and oxidation reactions to yield a second carcinogen, cinnabarinic acid. 3-HAT auto-oxidation to cinnabarinate required molecular oxygen and generated superoxide radicals and H2O2. Superoxide dismutase (SOD) accelerated 3-HAT auto-oxidation 4-fold, probably by preventing back reactions between superoxide and either the anthranilyl radical or the quinoneimine formed during the initial step of auto-oxidation. Catalase did not accelerate 3-HAT auto-oxidation, but it did prevent destruction of cinnabarinate by H2O2. Interconversion between oxyhemoglobin and methemoglobin occurred during 3-HAT auto-oxidation, although neither form of hemoglobin altered rates of 3-HAT auto-oxidation. Mn2+, Mn3+ and Fe3+-EDTA did not directly catalyze cinnabarinate formation in the absence of O2, but they did accelerate cinnabarinate formation under aerobic conditions.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/3-Hydroxyanthranilic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Anthranilic Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Catalase,
http://linkedlifedata.com/resource/pubmed/chemical/Oxazines,
http://linkedlifedata.com/resource/pubmed/chemical/Picolinic Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Pyridines,
http://linkedlifedata.com/resource/pubmed/chemical/Quinolinic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Quinolinic Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Superoxide Dismutase,
http://linkedlifedata.com/resource/pubmed/chemical/Tryptophan,
http://linkedlifedata.com/resource/pubmed/chemical/cinnabarinic acid,
http://linkedlifedata.com/resource/pubmed/chemical/picolinic acid
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jan
|
| pubmed:issn |
0006-2952
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
15
|
| pubmed:volume |
36
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
211-7
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:2949752-3-Hydroxyanthranilic Acid,
pubmed-meshheading:2949752-Anthranilic Acids,
pubmed-meshheading:2949752-Catalase,
pubmed-meshheading:2949752-Hydrogen-Ion Concentration,
pubmed-meshheading:2949752-Kinetics,
pubmed-meshheading:2949752-Oxazines,
pubmed-meshheading:2949752-Oxidation-Reduction,
pubmed-meshheading:2949752-Oxygen Consumption,
pubmed-meshheading:2949752-Picolinic Acids,
pubmed-meshheading:2949752-Pyridines,
pubmed-meshheading:2949752-Quinolinic Acid,
pubmed-meshheading:2949752-Quinolinic Acids,
pubmed-meshheading:2949752-Superoxide Dismutase,
pubmed-meshheading:2949752-Tryptophan
|
| pubmed:year |
1987
|
| pubmed:articleTitle |
Oxidative reactivity of the tryptophan metabolites 3-hydroxyanthranilate, cinnabarinate, quinolinate and picolinate.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|