Photochemical behavior of Safranine-Riboflavin complex in the degradation of folic acid

Autor(es)

Santos, Willy G. ^[1] ; Scurachio, Regina S. ^[1] ; Cardoso, Daniel R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY; v. 293, p. 32-39, NOV 1 2014.
• Citações Web of Science: 9

Resumo

The photochemistry of safranine complexed with riboflavin and the photoinduced electron transfer from folic acid to the complex were investigated by steady-state and time resolved absorption spectroscopy, and the photoproducts were further analyzed by LC-orbitrap-FT-MS. UV-vis spectra of the complex showed a decrease in the safranine band at 520 nm with increasing concentration of riboflavin, which was attributed to complex formation. A 1:1 (safranine:riboflavin) stoichiometry was determined using Job's method. Following safranine photoexcitation, there is formation of a radical pair in the complex by donation of an electron from ground-state riboflavin to excited-state safranine. The cation radical of riboflavin within this complex reacts with folic acid to yield FA(+){*}, which may accept an electron from the anion radical of safranine, avoiding the photobleaching of the safranine. In contrast, the reaction of the anion radical of non-complexed safranine with folic acid leads to safranine photobleaching. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 09/54040-8 - EMU: aquisição de um espectrômetro de massas de alta resolução Orbitrap para descoberta e elucidação estrutural compostos biologicamente ativos: aplicações em proteômica e biomarcadores, síntese, isolamento e caracterização de produtos naturais, estudos de sistemas redox em alimentos e síntese enzimática
• Beneficiário: Emanuel Carrilho
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
• Processo FAPESP: 12/19823-4 - Fototransientes de organoboranos gerados por fotólise direta e sensitização por flavinas.
• Beneficiário: Willy Glen Santos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado