title: Interaction of phloretin with the human red cell membrane and membrane lipids: evidence from infrared, Raman and ESR spectroscopy.
abstract: The transport inhibitor phloretin was bound to human red cell membrane and the concomitant structural changes were observed by spectroscopic methods. By the spin labeling method a decrease in fluidity of the membrane was found at 1 and 10 microM concentrations of the reagent. This result was obtained with the 2-(3-Carboxypropyl)-4,4-dimethyl-2-tridecyl-3-oxazolidinyloxyl, and the 2-4(14-Carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxazolidinyloxyl lipid spin labels. Infrared spectroscopy of modified membranes revealed an intensity increase of the POO- band at about 1250 cm-1. Moreover, a shift of the peak at 1050 cm-1 to 1100 cm-1 was observed in the presence of phloretin. Raman spectroscopy of the membranes did not contradict the results found with infrared and ESR spectroscopy: In the phloretin modified membrane we observed a lack of the band at 1085 cm-1, which leads to suggest that the POO- and/or C-C regions are less fluid. Changes of the extracted red cell membrane lipids were less characteristic, and the results differed from those found in red cell membrane.
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D008563:Membrane Lipids / Q000097:blood*; D010693:Phloretin / Q000494:pharmacology*; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D013113:Spin Labels
chemical_list: D008563:Membrane Lipids; D013113:Spin Labels; D010693:Phloretin