6533b82ffe1ef96bd1295c90
RESEARCH PRODUCT
Partition of Indicaxanthin in Membrane Biomimetic Systems. A Kinetic and Modeling Approach
Luciana SciasciaMaria Liria Turco LiveriM. A. LivreaLuisa TesoriereMario Allegrasubject
12-DipalmitoylphosphatidylcholinePyridinesLipid BilayersBetalain pigmentchemistry.chemical_compoundReaction rate constantGepasi simulation.biomimetic membraneLipid bilayervesiclephospholipidAqueous solutionChromatographyVesicleBilayerAqueous two-phase systemWaterGeneral ChemistryBinding constantBetaxanthinsPeroxidesKineticschemistryLiposomesPhysical chemistryDPPCGeneral Agricultural and Biological SciencesOxidation-ReductionIndicaxanthinSoftwaredescription
The solubilization site of indicaxanthin (Ind) in lipid bilayers was investigated by the kinetics of Ind oxidation by peroxyl radicals in water and in aqueous/L-alpha-dipalmitoyl-phosphatidylcholine (DPPC) vesicles, pH 7.4, and 37.0 and 48.0 degrees C, that is, in a gel-like and a crystal liquidlike bilayer state, respectively. The time-dependent Ind absorbance decay, matched with a successful simulation of the reaction kinetic mechanism by Gepasi software, supported a multistep pathway. Computer-assisted analysis allowed calculation of the rate constants associated with the reactions involved, the values of which decreased with increasing DPPC concentration. The binding constant calculated according to a pseudo two-phase distribution model did not vary with the physicochemical state of the vesicle, indicating location of Ind in a region whose state is not affected by temperature changes, at the interface between hydrophobic core and hydrophilic head groups. Other measurements carried out in the presence of dimyristoyl-phosphatidylcholine vesicles, indicated that the phytochemical was confined to the aqueous phase.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2009-11-19 |