论文部分内容阅读
乌苏酸(UA)为五环三萜羧基酸类化合物,是一种中药有效成分.它进入细胞的过程与膜脂分子有密切关系.选用生物膜系统中的膜脂分子二棕榈酰基磷脂酰胆碱(DPPC)为代表,通过LB(Langmuir-Blodgett)膜技术获得乌苏酸与DPPC混合单层膜的表面压力/平均分子面积(π-A)曲线.分析了混合单层膜的平均和过量分子面积、弹性系数等热力学参量,并用原子力显微镜进行了研究.比较了乌苏酸/DPPC与胆固醇/DPPC混合单层膜的异同.实验结果表明:乌苏酸能促使DPPC的凝聚;乌苏酸/DPPC两组分的物质的量比与混合单层膜的膜压对单层膜的压缩性、稳定性和热力学特性有影响,对单层膜中不同组分间的混合性以及分子间的相互作用具有重要的影响.
Uu acid is a pentacyclic triterpene carboxylic acid compound, which is an effective component of traditional Chinese medicine .Ultrasonic acid (UA) is closely related to the membrane lipid molecules in the process of its entry into the cell.Use the membrane lipid molecule dipalmitoylphosphatidic (DPPC), the surface pressure / average molecular area (π-A) curves of ursolic acid and DPPC mixed monolayers were obtained by LB (Langmuir-Blodgett) membrane technique.The average and Excess molecular area, elastic coefficient and other thermodynamic parameters were studied by atomic force microscopy.The similarities and differences between ursolic acid / DPPC and cholesterol / DPPC mixed monolayer were compared.The results showed that ursolic acid can promote the aggregation of DPPC, The ratio of the amount of acid to DPPC and the pressure of the mixed monolayer film have an influence on the compressibility, stability and thermodynamic properties of the monolayer film. The effects of mixing ratio of the different components in the monolayer film and intermolecular The interaction has a significant impact.