6533b82efe1ef96bd129332a
RESEARCH PRODUCT
Spectrophotometric evidence for the solubilization site of betalain pigments in membrane biomimetic systems.
M. A. LivreaRenato LombardoLuisa TesoriereMaria Liria Turco LiveriEgle PassanteLuciana Sciasciasubject
Lipid BilayersBetalainsPigmentchemistry.chemical_compoundBetalainvesiclePhospholipidsBetaninChromatographyChemistryVesicletechnology industry and agricultureGeneral Chemistrybetalain pigmentMembraneSolubilitySolubilizationSpectrophotometrybio-mimetic membranesvisual_artLiposomesvisual_art.visual_art_mediumBetalain Pigmentslipids (amino acids peptides and proteins)General Agricultural and Biological SciencesIndicaxanthindescription
The solubilization site of two betalain pigments, namely, betanin and indicaxantin, into l-alpha-dipalmitoyl-phosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC) vesicles was investigated by a spectrophotometric study. Pigment absorbance was monitored by varying phospholipid concentration, at a constant temperature that was varied in a range including the main phase transition temperature (Tm) of the relevant phospholipid bilayer. Maximum betanin absorption increased with the increase of DPPC concentration within the entire temperature range, reaching a plateau. The binding constant (Kb) of the pigment, calculated according to a pseudo-two-phase model, varied with the temperature, indicating that betanin is located at the hydrophobic interior of the bilayer. Other measurements of binding of betanin to DMPC and of indicaxanthin to either DPPC or DMPC vesicles ruled out that these compounds were solubilized in the hydrophobic interior of these bilayers.
year | journal | country | edition | language |
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2007-03-27 | Journal of agricultural and food chemistry |