Mapping the structure-activity relationship of β-sitosteryl fatty acid esters in condensing phospholipid monolayers  

作　　者：Worawan PANPIPAT Hasene KESKIN Zheng GUO 

机构地区：[1]Department of Engineering, Faculty of Science, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark [2]Department of Food Engineering, Faculty of Engineering, University of Gaziantep, 27310 Gaziantep, Turkey

出　　处：《Frontiers of Chemical Science and Engineering》2015年第1期105-113,共9页化学科学与工程前沿（英文版）

摘　　要：Abstract The phase behavior of twelve synthesized β- sitosteryl fatty acid esters with acyl moieties with different chain lengths （C2：0-C18：0） and different degrees of unsaturation （C18：1-C18：3） were investigated in pure and mixed Langmuir monolayers with phospholipids. The surface-pressure isotherms showed that short chain fl- sitosteryl fatty acid esters gave smaller mean molecular areas and had decreased monolayer stability and the long chain steryl esters did not produce collapsed plateaus. All the steryl esters displayed strong condensing effects, but there was a pronounced structural dependency： medium chain esters （C8 and C 10） were less efficient than short and long chain esters. Atomic force microscopy imaging demonstrated that monolayers mixed with dipalmitoyl phosphatidylcholine （DPPC） displayed both DPPC-rich and steryl lipid-rich domains. However, the height and area differences between the two phases and the roughness and morphologic patterns were very dependent on the steryl lipid concentrations as well as the length, the degree of unsaturation and the molecular conformations of the acyl segments. These findings not only provide a better understanding of the interactions between phytosteryl hydrophobic derivatives and biomembranes, but also may be of general use for the design and engineering of phytosterol structural derivations for specific food and pharmaceutical applications.Abstract The phase behavior of twelve synthesized β- sitosteryl fatty acid esters with acyl moieties with different chain lengths （C2：0-C18：0） and different degrees of unsaturation （C18：1-C18：3） were investigated in pure and mixed Langmuir monolayers with phospholipids. The surface-pressure isotherms showed that short chain fl- sitosteryl fatty acid esters gave smaller mean molecular areas and had decreased monolayer stability and the long chain steryl esters did not produce collapsed plateaus. All the steryl esters displayed strong condensing effects, but there was a pronounced structural dependency： medium chain esters （C8 and C 10） were less efficient than short and long chain esters. Atomic force microscopy imaging demonstrated that monolayers mixed with dipalmitoyl phosphatidylcholine （DPPC） displayed both DPPC-rich and steryl lipid-rich domains. However, the height and area differences between the two phases and the roughness and morphologic patterns were very dependent on the steryl lipid concentrations as well as the length, the degree of unsaturation and the molecular conformations of the acyl segments. These findings not only provide a better understanding of the interactions between phytosteryl hydrophobic derivatives and biomembranes, but also may be of general use for the design and engineering of phytosterol structural derivations for specific food and pharmaceutical applications.

关 键 词：β-sitosteryl fatty acid esters DIPALMITOYLPHOSPHATIDYLCHOLINE Langmuir monolayer condensingeffect structure-activi .ty relationship 

分 类 号：TQ225.24[化学工程—有机化工] O647.9[理学—物理化学]