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Oxidative conjugation of chlorogenic acid with glutathione: Structural characterization of addition products and a new nitrite-Promoted pathway
- Source :
-
Bioorganic & Medicinal Chemistry . Nov2003, Vol. 11 Issue 22, p4797. 9p. - Publication Year :
- 2003
-
Abstract
- Chlorogenic acid (1), a cancer chemopreventive agent widely found in fruits, tea and coffee, undergoes efficient conjugation with glutathione (GSH), in the presence of horseradish peroxidase/H2O2 or tyrosinase at pH 7.4, to yield three main adducts that have been isolated and identified as 2-S-glutathionylchlorogenic acid (3), 2,5-di-S-glutathionylchlorogenic acid (4) and 2,5,6-tri-S-glutathionylchlorogenic acid (5) by extensive NMR analysis. The same pattern of products could be obtained by reaction of 1 with GSH in the presence of nitrite ions in acetate buffer at pH 4. Mechanistic experiments suggested that oxidative conjugation reactions proceed by sequential nucleophilic attack of GSH on ortho-quinone intermediates. Overall, these results provide the first complete spectral characterization of the adducts generated by biomimetic oxidation of 1 in the presence of GSH, and disclose a new possible nitrite-mediated conjugation pathway of 1 with GSH at acidic pH of physiological relevance. [Copyright &y& Elsevier]
- Subjects :
- *CHLOROGENIC acid
*CHEMOPREVENTION
*PHENOL oxidase
*NITRITES
Subjects
Details
- Language :
- English
- ISSN :
- 09680896
- Volume :
- 11
- Issue :
- 22
- Database :
- Academic Search Index
- Journal :
- Bioorganic & Medicinal Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 10985064
- Full Text :
- https://doi.org/10.1016/S0968-0896(03)00460-7