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1,3-diene probes for detection of triplet carbonyls in biological systems.
Chem Res Toxicol 2007; 20(8):1162-9CR

Abstract

Electronically excited triplet carbonyls are formed during the oxidative degradation of polyunsaturated fatty acids, amino acids, and beta-dicarbonyl metabolites. Due to their long lifetime and high alkoxyl radical-like reactivity, triplet carbonyls may initiate deleterious reactions in biological systems. Here we study the quenching properties of conjugated dienes, specifically 2,4-hexadienoate (sorbate) and its alkyl ester, on triplet acetone generated chemically (thermolysis of tetramethyl-1,2-dioxetane) or enzymatically (horseradish peroxidase-catalyzed aerobic oxidation of isobutanal). Triplet acetone quenching rates were near diffusion control (k q = 10 (8)-10 (9) M (-1) s (-1)) and accompanied by diene cis-trans isomerization. None of the dienes displays antioxidant activity in classical systems known to generate reactive oxygen species: superoxide anion radical, hydroxyl radical, alkoxyl and alkylperoxyl radicals, or singlet oxygen. Experiments with model systems used widely to study lipid peroxidation showed that sorbate can inhibit mitochondrial swelling induced by enzymically formed triplet benzophenone and quench the chemiluminescence of microsome preparations challenged with iron and ascorbate. Altogether, our data indicate that conjugated dienes can be used as specific quenchers of triplet carbonyls formed in biological systems during oxidative stress. Moreover, they suggest that the well-known food preservative properties of sorbate may be due to its triplet carbonyl quenching activity.

Authors+Show Affiliations

Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17630714

Citation

Velosa, Adriana C., et al. "1,3-diene Probes for Detection of Triplet Carbonyls in Biological Systems." Chemical Research in Toxicology, vol. 20, no. 8, 2007, pp. 1162-9.
Velosa AC, Baader WJ, Stevani CV, et al. 1,3-diene probes for detection of triplet carbonyls in biological systems. Chem Res Toxicol. 2007;20(8):1162-9.
Velosa, A. C., Baader, W. J., Stevani, C. V., Mano, C. M., & Bechara, E. J. (2007). 1,3-diene probes for detection of triplet carbonyls in biological systems. Chemical Research in Toxicology, 20(8), pp. 1162-9.
Velosa AC, et al. 1,3-diene Probes for Detection of Triplet Carbonyls in Biological Systems. Chem Res Toxicol. 2007;20(8):1162-9. PubMed PMID: 17630714.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - 1,3-diene probes for detection of triplet carbonyls in biological systems. AU - Velosa,Adriana C, AU - Baader,Wilhelm J, AU - Stevani,Cassius V, AU - Mano,Camila M, AU - Bechara,Etelvino J H, Y1 - 2007/07/13/ PY - 2007/7/17/pubmed PY - 2007/12/6/medline PY - 2007/7/17/entrez SP - 1162 EP - 9 JF - Chemical research in toxicology JO - Chem. Res. Toxicol. VL - 20 IS - 8 N2 - Electronically excited triplet carbonyls are formed during the oxidative degradation of polyunsaturated fatty acids, amino acids, and beta-dicarbonyl metabolites. Due to their long lifetime and high alkoxyl radical-like reactivity, triplet carbonyls may initiate deleterious reactions in biological systems. Here we study the quenching properties of conjugated dienes, specifically 2,4-hexadienoate (sorbate) and its alkyl ester, on triplet acetone generated chemically (thermolysis of tetramethyl-1,2-dioxetane) or enzymatically (horseradish peroxidase-catalyzed aerobic oxidation of isobutanal). Triplet acetone quenching rates were near diffusion control (k q = 10 (8)-10 (9) M (-1) s (-1)) and accompanied by diene cis-trans isomerization. None of the dienes displays antioxidant activity in classical systems known to generate reactive oxygen species: superoxide anion radical, hydroxyl radical, alkoxyl and alkylperoxyl radicals, or singlet oxygen. Experiments with model systems used widely to study lipid peroxidation showed that sorbate can inhibit mitochondrial swelling induced by enzymically formed triplet benzophenone and quench the chemiluminescence of microsome preparations challenged with iron and ascorbate. Altogether, our data indicate that conjugated dienes can be used as specific quenchers of triplet carbonyls formed in biological systems during oxidative stress. Moreover, they suggest that the well-known food preservative properties of sorbate may be due to its triplet carbonyl quenching activity. SN - 0893-228X UR - https://www.unboundmedicine.com/medline/citation/17630714/13_diene_probes_for_detection_of_triplet_carbonyls_in_biological_systems_ L2 - https://dx.doi.org/10.1021/tx700074n DB - PRIME DP - Unbound Medicine ER -