title: Ultrathin films of lipids to investigate the action of a flavonoid with cell membrane models.
abstract: Understanding the role of natural compounds whose pharmaceutical activity is associated with cell membranes is fundamental to comprehending the biochemical processes that occur on membrane surfaces. In this work, we examined the action of 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one, known as quercetin, QCT, in lipid Langmuir monolayers at the air-water interface, which served as a model for half of a membrane. The surface pressure-area isotherms for 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid monolayers exhibited a noticeable shift to higher areas in the presence of the flavonoid, which indicated the incorporation of QCT into the monolayer and expansion of the film. Also the flavonoid incorporation diminishes the monolayer surface elasticity for DPPC and causes a relative decrease of the intensity for C-H stretch bands, pointing to a disruption of the packed order of DPPC. These results can be associated to the interaction between QCT and cell membrane surfaces during biochemical processes, which may influence its pharmaceutical properties.
authors.affiliation: Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of Sao Paulo, Diadema, SP, Brazil.
authors.forename: João Victor Narducci
authors.initials: JV
authors.lastname: Ferrreira
authors.affiliation: Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of Sao Paulo, Diadema, SP, Brazil.
authors.forename: Simone Dos S
authors.initials: Sdos S
authors.lastname: Grecco
authors.affiliation: Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of Sao Paulo, Diadema, SP, Brazil.
authors.forename: João Henrique G
authors.initials: JH
authors.lastname: Lago
authors.affiliation: Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of Sao Paulo, Diadema, SP, Brazil. Electronic address: lcaseli@unifesp.br.
authors.forename: Luciano
authors.initials: L
authors.lastname: Caseli
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000031:analogs & derivatives / Q000737:chemistry; D002462:Cell Membrane / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry*; D011794:Quercetin / Q000031:analogs & derivatives* / Q000737:chemistry; D013499:Surface Properties
chemical_list: D008563:Membrane Lipids; D015060:1,2-Dipalmitoylphosphatidylcholine; C012526:quercitrin; C081581:colfosceril palmitate; D011794:Quercetin
keywords: Air–water interface; Flavonoid; Langmuir monolayers; Quercetin; Surface Infrared Spectroscopy