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本文合成了一系列含有胆固醇和4-(反式-正烷基环己基)苯甲酸结构单元的新型双液晶基元液晶化合物。这些化合物中两个介晶基元是利用不同长度的氧烷酰基连接在一起。利用FT-IR、MS、1H NMR、POM、DSC 表证了所得化合物的结构和介晶性,并选择几种双液晶基元液晶测定了它们的机械黏度和在主体液晶中的螺旋扭曲力(HTP)。结果表明,绝大多数化合物显示较低相变温度的胆甾相(N*),并且被选择的化合物的平均机械黏度和螺旋扭曲力类似于或优于胆甾醇任酸酯。  相似文献   
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Red ginseng has been gradually discovered to have pharmacological and physiological effects. It is well known that the most important bioactive components of ginseng are ginsenosides. The nootropic effect of ginsenosides from nine different red ginseng extracts was evaluated here. Nine groups of mice were perfused with different concentrations of nine red ginseng extracts, respectively, and two groups of mice with distilled water. The nootropic effect of ginsenosides on mice was evaluated with behavior tests and a biochemical indicator study. The extracts were identified by rapid resolution liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry(RRLC-Q-TOF-MS). Furthermore, principal component analysis(PCA) was used to analyze the contribution of chemical components from different ginseng groups. The extracts with the most and the weakest effective nootropic were found. It is notable that extract processing is a very important factor to decide pharmacological functions of ginseng extracts. As a conclusion, the most effective extract method for ginsenosides has been found. A panel of 13 ginsenosides has been screened out as chemical markers with nootropic effect, which include high level ginsenosides Ra0, Rb1, Rc, Rb2, Rb3, Re, Rd, and Rg1 and low level ginsenosides mRb1, mRc, mRb2, mRd, and F2. Low level ginsenosides were first time to be discovered as possible nootropic compounds. This method may shed light on fast discovery of bioactive compounds of medicinal plants with low level compounds.  相似文献   
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研究四君子汤在2型糖尿病大鼠体内的药代动力学。 将四君子汤水提物以18 g/kg给正常大鼠和2型糖尿病大鼠灌胃,分别在不同时间点取尿液和粪便,检测其成分及代谢产物的含量;比较正常大鼠和2型糖尿病大鼠的药代动力学参数。 采用快速高分辨液相色谱-质谱联用技术对人参皂苷Rc、甘草甜素及其脱糖代谢物进行表征。 结果表明,四君子汤中人参皂苷Rc和甘草甜素在2型糖尿病大鼠体内的累计排泄率均高于正常大鼠,大部分人参皂苷通过尿液排出体外、粪便代谢为稀有人参皂苷;大部分甘草甜素在尿液和粪便中转化为甘草次酸,2型糖尿病大鼠与正常大鼠人参皂苷Rc和甘草甜素的药代动力学参数存在明显差异。 初步总结了四君子汤在体内的药代动力学机制和代谢途径。本分析方法具有高度自动化,灵敏性和准确性,这将有助于四君子汤的临床研究的不断发展。  相似文献   
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