Effect of phloretin on the dipole potential of phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol monolayers.
The effect of phloretin on the potential of phosphatidylcholine (PC), phosphatidylethanolamine (PE,) and phosphatidylglycerol (PG) monolayers below and above the phase transition in mixtures of different PC/PE ratios with and without cholesterol of ester and ether phospholipids have been determined. The effectiveness of phloretin to decrease the dipole potential of monolayers in the fluid state is lessened by the moieties esterified to the phosphate group in the sequence choline > ethanolamine > glycerol. These effects on the dipole potential of monolayers are independent of the presence of carbonyls. In addition, in the gel state phloretin does not affect the dipole potential on dimyristoylphosphatidylethanolamine, although it is very pronounced in dimyristoylphosphatidylcholine. The changes of the dipole potential induced by phloretin were correlated with the packing of the lipids and with the formation of intermolecular hydrogen bonds between adjacent phospholipid molecules. These results may be indicative of the different distribution of polarized water around the phosphate groups imposed by the surrounding environment.
Laboratorio de Fisicoquímica de Membranas Lipídicas y Liposomas, Cátedra de Química General e Inorgánica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 2 degrees Piso (1113), Capital Federal, Argentina.
Fabiana
F
Lairion
E Anibal
EA
Disalvo
D002784:Cholesterol / Q000737:chemistry; D044367:Phase Transition; D010693:Phloretin / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry*; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D010715:Phosphatidylglycerols / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry; D055672:Static Electricity; D013499:Surface Properties
D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010715:Phosphatidylglycerols; D010743:Phospholipids; C483858:phosphatidylethanolamine; D002784:Cholesterol; D010693:Phloretin