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荷花碱与牛血清白蛋白的相互作用 总被引:5,自引:0,他引:5
利用多种光谱技术研究了在pH7.40的Tris-HCl缓冲体系下,荷花碱与牛血清白蛋白(BSA)的相互作用。研究发现荷花碱对牛血清白蛋白有较强的荧光猝灭作用且为静态猝灭。用Stern-Volmer和Line weaver-Burk方程处理荧光猝灭数据,得到反应的结合常数在293K时为1.70×104L/mol,结合的ΔH°=-20.2kJ/mol,ΔS°=12.0J/(K.mol)。该药物与血清白蛋白之间的作用力为疏水作用和静电作用。根据Frster非辐射能量转移理论求得荷花碱与BSA相互结合时,其供体-受体间的距离为2.59nm。用圆二色谱等手段表明结合对蛋白的构象产生了影响。同时考察了中药活性成分甘草次酸和脂肪酸对结合的影响。 相似文献
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应用近红外光谱技术并结合化学计量学建立杜仲中松脂素二葡萄糖苷(PDG)和京尼平苷酸(GPA)含量测定模型。以积分球漫反射方式采集近红外光谱数据,应用一阶微分、多元散射校正(MSC)等优选光谱数据预处理方法和竞争自适应加权采样(CARS)筛选最优波长变量,采用偏最小二乘法(PLS)和交叉验证法建立PDG和GPA的定标模型。PDG和GPA的定标模型显示出良好的预测效果,其校正集的相关系数分别为0.961 5和0.958 3,交互验证均方差分别为0.001 5和0.006 4。表明此快速预测模型准确可靠,适合快速测定杜仲中的PDG和GPA,为杜仲质量控制在线化提供了新思路。 相似文献
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Sedimentation rate of sediments on the continental slope of the South China Sea has been determined by the Th_(ex)~(230) method. Results show that in the upper part of the core from the surface layer down to 48 cm there might have occurred a downslope, reflecting a discontinuous depositional process and palaeoclimate becoming warmer; in the middle section of the core the activities of Th_(ex)~(230) show an exponential decrease with increasing depths and depoaitional rate is 1.6mm/1000 years, and sediments might have been formed in a cold and deep-water environment: in the core from 90cm downward there might have been an active sedimentary environment with a warmer palaeoclimate.Based on the contents of U and Th, U/Th ratios and their relationships with Fe, Mn, Corg and P in all layers of the core, it is inferred that materials of the studied waters are mainly of terrestrial phase with a portion of authigenous constituents. 相似文献
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甲基莲心碱与人血清白蛋白相互作用的研究 总被引:1,自引:1,他引:0
荧光光谱、圆二色谱等多种光谱技术研究甲基莲心碱(NF)与人血清白蛋白(HSA)的相互作用,以Stern-Volmer和Lineweaver-Burk方程处理数据。甲基莲心碱对人血清白蛋白有较强的荧光猝灭作用并为静态猝灭,主要作用力为疏水作用和静电作用。309K下NF与HSA相互作用的结合常数为1.39×104L.mol-1,NF-色氨酸残基之间的距离为2.70nm,热力学参数ΔH0=-13.0KJ·mol-1,ΔS0=37.2J.(K.mol)-1。NF的结合使蛋白α-螺旋百分数增加。中药活性成分甘草次酸等和内源脂肪酸对结合的影响较少。 相似文献
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