Enolizable carbonyl and imino metabolites may act as endogenous sources of reactive oxygen species
Ciênc. cult. (Säo Paulo)
; 47(5/6): 346-57, Sept.-Oct. 1995. ilus
Article
in En
| LILACS
| ID: lil-186431
Responsible library:
BR1.1
RESUMO
Highly reactive oxyradicals and electronically excited triplet carbonyls can be generated in vitro by iron complexes and heme enzyme-catalyzed aerobic oxidation of synthetic or naturally occurring substances capable of enolization in aqueous medium. Monoenols and enamines, obtained by (alpha-methyne-carbonyl and -imine enolization, undergo dioxygen insertion and ultimately originate triplet species; e.g., isobutanal, 3-methylacetoacetone, Schiff bases. In turn, (alpha-hydroxy- and (alpha-aminocarbonyls (e.g., carbohydrates, 5-aminolevulinic acid) tautomerize to enediols and enolamines and yield oxyradicals, initiated by electron transfer to dioxygen, as polyphenols (e.g., 6-hydroxydopamine) and polyphenolamines do. Free radicals and excited species have been implicated in several normal and pathological processes. We here briefly review our contributions to this research area, emphasizing a possible in vivo prooxidant role for 5-aminolevulinic acid, the heme precursor accumulated in several porphyric disorders (e.g., lead poisoning, acut intermittent porphyria, tyrosinosis).
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Index:
LILACS
Main subject:
In Vitro Techniques
/
Reactive Oxygen Species
/
Aminolevulinic Acid
Limits:
Animals
/
Humans
Language:
En
Journal:
Ciênc. cult. (Säo Paulo)
Journal subject:
CIENCIA
Year:
1995
Type:
Article