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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Photooxidation of Other B-Vitamins as Sensitized by Riboflavin

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Arrivetti, Leandro de O. R. [1] ; Scurachio, Regina S. [1] ; Santos, Willy G. [1] ; Papa, Thiago B. R. [1] ; Skibsted, Leif H. [2] ; Cardoso, Daniel R. [1]
Total Authors: 6
[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
[2] Univ Copenhagen, Dept Food Sci, DK-1958 Frederiksberg C - Denmark
Total Affiliations: 2
Document type: Journal article
Source: Journal of Agricultural and Food Chemistry; v. 61, n. 31, p. 7615-7620, AUG 7 2013.
Web of Science Citations: 4

Pyridoxal phosphate (PLP) was found to deactivate triplet-excited riboflavin (Rib) in aqueous solution with a deactivation constant of 3.0 +/- 0.1 X 10(8) L mol(-1) s(-1) at 25 degrees C. Likewise, PLP was found to quench the fluorescence emission of (1)Rib{*} with (1)k(q) = 1.0 +/- 0.1 x 10(11) L mol(-1) s(-1) as determined by steady state fluorescence. The rather high quenching constant suggests the formation of a ground state complex, which was further confirmed by time-resolved fluorescence measurements to yield a (1)Rib{*} deactivation constant of 3.4 +/- 0.4 x 10(10) L mol(-1) s(-1). Triplet quenching is assigned as one-electron transfer rather than hydrogen-atom transfer from PLP to (3)Rib{*}, as the reaction quantum yield, Phi = 0.82, is hardly influenced by solvent change from water to D2O, Phi = 0.78. Neither biotin nor niacin deactivates the singlet- or triplet-excited riboflavin as it is expected from their higher oxidation potentials E > 2 V vs NHE. (AU)

FAPESP's process: 09/54040-8 - Acquisition of a high-resolution Orbitrap mass spectrometer for the discovery and structural analysis of biologically active compounds: applications in proteomics, biomarkers, synthesis, isolation, and characterization of natural products, studies of redox systems in food and enzymatic synthesis
Grantee:Emanuel Carrilho
Support type: Multi-user Equipment Program
FAPESP's process: 11/51555-7 - Bread and meat for the future
Grantee:Daniel Rodrigues Cardoso
Support type: Regular Research Grants