Flavinium Catalysed Photooxidation: Detection and Characterization of Elusive Peroxyflavinium Intermediates.

ABSTRACT: Flavin-based catalysts are photoactive in the visible range which makes them useful in biology and chemistry. Herein, we present electrospray-ionization mass-spectrometry detection of short-lived intermediates in photooxidation of toluene catalysed by flavinium ions (Fl⁺ ). Previous studies have shown that photoexcited flavins react with aromates by proton-coupled electron transfer (PCET) on the microsecond time scale. For Fl⁺ , PCET leads to FlH^.+ with the H-atom bound to the N5 position. We show that the reaction continues by coupling between FlH^.+ and hydroperoxy or benzylperoxy radicals at the C4a position of FlH^.+ . These results demonstrate that the N5-blocking effect reported for alkylated flavins is also active after PCET in th

SUBMITTER: Zelenka J 

PROVIDER: S-EPMC6852162 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature