Monolayers (Langmuir films) behavior of multi-component systems composed of a bile acid with different sterols and with their 1:1 mixtures.
Monolayers (Langmuir films) behavior of multi-component systems composed of a bile acid with different sterols and with their 1:1 mixtures.
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DOI：
10.1016/j.colsurfb.2007.02.017
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发表时间：
2007-08
期刊：
影响因子：
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通讯作者：
S. Nagadome;N. Suzuki;Yauko Mine;Takeo Yamaguchi;H. Nakahara;O. Shibata;Chien-Hsiang Chang;G. Sugihara
中科院分区：
文献类型：
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作者：
S. Nagadome;N. Suzuki;Yauko Mine;Takeo Yamaguchi;H. Nakahara;O. Shibata;Chien-Hsiang Chang;G. Sugihara
Langmuir膜的不同物理化学性质（单层）由胆汁酸、脱氧胆酸（DC）与各种植物甾醇（如豆甾醇（Stig）、β-谷甾醇（Sito）和菜油甾醇（Camp））和甾烷醇、胆甾烷醇（Chsta）以及动物甾醇、胆固醇（Ch）[这些甾醇和Chsta缩写为St]和DC与1：1 St混合物的10种混合体系组成;（Ch+Chsta），（Ch+Stig），（Stig+Chsta）、（Ch+Sito）和（Ch+Camp）在5 M NaCl水溶液的底物上（pH 1.2）在25°C下，根据每分子的平均表面积（Am）、部分分子面积（PMA）、表面过量吉布斯能（ΔG（ex））、相互作用参数（Ip）和活度系数（f1和f2）在每个二进制的二维相位中（或三元）组分体系和成膜的弹性（Cs-1）;基于在离散的表面压力下作为DC/St（s）混合物中Sts的摩尔分数（Xst）的函数的相应的表面压力（π）对Amisotherms对这些进行分析。值得注意的调查结果是：（i）所有二元组分体系都形成了由（a）溶解痕量St分子的DC主导膜和（B）溶解少量DC分子的St主导膜组成的补丁膜型单层，（ii）二维相的DC在恒定压力（πC1）下表现出从LE膜到LC膜的转变，并伴有压缩;以及Ip被发现极大地依赖于（a）DC与不同St种类的组合和（B）通过DC与St的混合比的差异而显著变化。压缩性（或弹性）分析和荧光显微镜图像可以支持上述结果以及解释。
Different physicochemical properties of Langmuir films (monolayers) composed of 10 mixed systems of a bile acid, deoxycholic acid (DC) with various plant sterols, such as stigmasterol (Stig), β-sitosterol (Sito) and campesterol (Camp) and a stanol, cholestanol (Chsta) in addition to an animal sterol, cholesterol (Ch) [these sterols and Chsta are abbreviated as St] and DC with 1:1 St mixtures; (Ch+Chsta), (Ch+Stig), (Stig+Chsta), (Ch+Sito) and (Ch+Camp) on the substrate of 5M aqueous NaCl solution (pH 1.2) at 25°C, were investigated in terms of mean surface area per molecule (Am), the partial molecular area (PMA), surface excess Gibbs energy (ΔG(ex)), interaction parameter (Ip) as well as activity coefficients (f1and f2) in 2-D phase of each binary (or ternary) component system and elasticity (Cs−1) of formed films; these were analyzed on the basis of the respective surface pressure (π) versus Amisotherms as a function of mole fraction of Sts (Xst) in the DC/St(s) mixtures at discrete surface pressures. Notable findings are: (i) all the binary component systems did form patched film type monolayers consisting of (a) DC-dominant film solubilizing a trace amount of St molecules and (b) St dominant film dissolving a small amount of DC molecules, (ii) DC in 2-D phase exhibited a transition from LE film to LC film at a constant pressure (πC1) accompanied by compression and (iii) ΔG(ex)as well as Ipwas found to be greatly dependent on (a) the combinations of DC with different St species and (b) to be markedly varied by a difference in mixing ratio of DC to Sts. Compressibility (or elasticity) analyses and fluorescence microscopy images could support the above findings as well as interpretation.