First steps in the photochemistry of folate in alkaline medium

ANDRÉS H. THOMAS; FERNANDO S. GARCÍA EINSCHLAG; MARIO R. FÉLIZ; ALBERTO L. CAPPARELLI

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

Año: 1998 p. 187 - 190

1010-6030

A laser flash photolysis study is reported on alkaline solutions of folic acid in absence of dioxygen. Spectra of the intermediates and their decays are analysed. A biexponential fit of the experimental decay can be observed in the resolution time window of the technique. Intermediates spectra obtained in laser flash photolysis were compared with those generated in pulse radiolysis experiments performed on these solutions under oxidative and reductive conditions. Conventional flash photolysis were also applied in this studies in absence of O2. In this case two processes are detected, one in the millisecond time window and a very slow process which can be followed by normal spectrophotometry after flashing solutions. The experimental behaviour of this system is compared with those reported on pterines derivatives, where absorption changes induced by flash photolysis have been attributed to triplet excited state. The evidence presented here shows that folate suffers an early photochemical transformation. Radicals generation as a consequence of the absorption of radiation is postulated in order to give a plausible explanation of the experimental results.