Carotenoid radical anions and their protonated derivatives.
In this study, we report the protonation reactions for astaxanthin and canthaxanthin radical anions in methanol, alkaline methanol, and aqueous 2% Triton X-100 at different pH values. The pKa values for the corresponding alpha-hydroxy radical derivatives of astaxanthin, canthaxanthin, and beta-apo-8'-carotenal were estimated in 2% Triton X-100. Also, the effects of the microenvironment and the structure of the carotenoids on the protonation rate constant are discussed.
El-Agamey
Ali
A
School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG, UK. a.a.g.el-agamey@chem.keele.ac.uk
Edge
Ruth
R
Navaratnam
Suppiah
S
Land
Edward J
EJ
Truscott
T George
TG
D000838:Anions; D002338:Carotenoids / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D017830:Octoxynol; D011522:Protons
D000838:Anions; D011522:Protons; D002338:Carotenoids; D017830:Octoxynol