The kinetics of change in the fluidity of liposome membranes, obtained in the process of sonication of Egg Yolk Lecithin (EYL), with the admixture of organic tin compounds, was investigated. Five compounds were selected for the research: three differed in the length of hydrocarbon chains, (CH3)4Sn, (C2H5)4Sn, and (C3H7)3SnCl, whereas two differed in the number of aromatic rings, (C6H5)2SnCl2 and (C6H5)3SnCl. The concentration of the compounds in proportion to EYL was 2 mol-%. Electron Spin (paramagnetic) Resonance (ESR) was applied using two spin probes TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) and 16-DOXYL-stearic acid methyl ester (2-ethyl-2-(15-methoxy-15-oxopentadecyl)-4,4-dimethyl-3-oxazolidinyloxyl) localized at different sites within the membrane, to determine the spectroscopic parameters: partition (F) and rotation correlation time (τ), related to the membrane's fluidity. The ESR spectroscopic spectra of investigated samples were recorded from the moment of introducing the admixture to membranes for 180h. Analysing the obtained results, the following conclusions can be drawn: chain compounds slightly stiffened the membrane both on the inside (hydrophobic) layer and on the surface one, whereas ring compounds resulted in fluidization of the membrane—stronger in the case of the two-layer middle and weaker with reference to the surface layer.

中文翻译：

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掺杂有机锡化合物的脂质体膜的流动性：ESR 研究

研究了在蛋黄卵磷脂 (EYL) 与有机锡化合物的混合物超声处理过程中获得的脂质体膜流动性的变化动力学。选择了五种化合物进行研究：三种化合物的烃链长度不同，(CH3)4Sn、(C2H5)4Sn 和 (C3H7)3SnCl，而两种化合物的芳环数量不同，(C6H5)2SnCl2 和 (C6H5) )3SnCl。与 EYL 成比例的化合物浓度为 2 mol-%。使用两个自旋探针 TEMPO（2,2,6,6-四甲基哌啶-1-氧基）和 16-DOXYL-硬脂酸甲酯（2-乙基-2-（15-甲氧基-15-氧代十五烷基）-4,4-二甲基-3-恶唑烷氧基）定位在膜内的不同位点，以确定光谱参数：分配（F）和旋转相关时间（τ），与膜的流动性有关。从将混合物引入膜的那一刻起 180 小时记录所研究样品的 ESR 光谱。分析获得的结果，可以得出以下结论：链状化合物在内部（疏水）层和表面层上都使膜略微变硬，而环状化合物导致膜流化——在两种情况下更强层中间和较弱的参考面层。