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LASER FLASH PHOTOKINETIC STUDIES OF ROSE BENGAL SENSITIZED PHOTODYNAMIC INTERACTIONS OF NUCLEOTIDES AND DNA
Author(s) -
Lee Plato C. C.,
Rodgers Michael A. J.
Publication year - 1987
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.1751-1097.1987.tb08407.x
Subject(s) - rose bengal , flash photolysis , singlet oxygen , chemistry , photochemistry , guanine , quenching (fluorescence) , superoxide , nucleotide , oxygen , xanthene , reaction rate constant , fluorescence , kinetics , biochemistry , organic chemistry , physics , quantum mechanics , gene , enzyme
— Laser flash photolysis studies of the production of the triplet state of the xanthene dye, rose bengal (RB), have been carried out. The reactions of this state with oxygen to form singlet oxygen and the superoxide anion radical have been observed and yields measured. Quenching of RB(T 1 ) by oxygen leads to approximately 75% singlet oxygen and 20% superoxide. The reactivity of these species‐RB(T 1 ), O 2 ( 1 Δ g ) and O 2 ‐ —with four nucleotides and DNA have been determined. Only guanine residues showed any noticeable reaction at neutral pH. At higher pH guanine rate constants increased. The consequences to biological photodynamic processes are discussed.