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TRIPLET STATE STUDIES OF FLAVINS BY ELECTRON PARAMAGNETIC RESONANCE—I
Author(s) -
Shiga T.,
Piette L.H.
Publication year - 1964
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1964.tb08777.x
Subject(s) - flavin group , chemistry , triplet state , photochemistry , electron paramagnetic resonance , paramagnetism , resonance (particle physics) , radical , molecule , nuclear magnetic resonance , atomic physics , biochemistry , organic chemistry , enzyme , physics , quantum mechanics
Abstract— The triplet state of flavin derivatives and d‐amino acid oxidase was observed by electron paramagnetic resonance at 77°K. Flavin triplets (Δ m =± 2) originate from the isoalloxazine ring and are resonant at 1560 guass.The half‐life of the FMN triplet in 1 N HCl is 15 nisec.This life‐time is prolonged indirectly by the presence of paramagnetic species, such as oxygen or free radicals. The flavin triplet state is pH dependent.In neutral solution the nlaximum triplet yield is obtained and the longest life‐time is observed.The triplet state is affected by intra‐and inter‐molecular complex formation, FAD is partially quenched by indirectly substituted adenine.Tryptophan quenches completely the FMN triplet.The FAD triplet of d‐amino acid oxidase is enhanced but the life‐time is shortened relative to a pure FAD solution.