Photochemical hydroxylation of 7,8-dimethylalloxazine (lumichrome)--a flash photolysis study

Autor:	R. R. Düren, W. Berends, R. H. Dekker, H. C. A. Van Beek
Rok vydání:	1976
Předmět:	Aqueous solution Photolysis Chemistry Photodissociation Quantum yield Protonation General Medicine Flavin group Photochemistry Hydroxylation Biochemistry chemistry.chemical_compound Kinetics Reaction rate constant Flavins Flash photolysis Physical and Theoretical Chemistry Oxidation-Reduction
Zdroj:	Photochemistry and photobiology. 23(3)
ISSN:	0031-8655
Popis:	— Flash photolysis experiments on the hydroxylation of lumichrome (L) in aqueous 0.5 M H2SO4 solution in the presence of O2 or Ni2+ as triplet quenchers and quantum yield measurements confirm the assignment of the photoreactive species to the protonated form of the excited singlet state. A mechamism concerning the photochemical step is proposed, accounting for the formation of protonated 9-hydroxy-5,10-dihydrolumichrome (LOH3+). This primary stable photoproduct was characterized by spectral and kinetic data. The dark reactions originating from LOH3+ were investigated, and data regarding the successive steps are presented. The reaction LOH3+ L LO + LH3+ is demonstrated to be a two-electron reduction. The rate constant for the reaction of LH2+ with O2 is much larger than that for the oxidation of LH3+ by oxygen.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a743c731592841b8ae42015f997ae6c3 https://pubmed.ncbi.nlm.nih.gov/1265142 Zobrazit plný text záznamu Plný text