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Experimental and Theoretical Studies on Interaction of Environmental Estrogens with Cyclodexrtins as a Receptor Model

环境雌激素与环糊精作为受体模型相互作用的实验和理论研究

基本信息

批准号：
13680125
负责人：
IHARA Yasuji
金额：
$ 2.18万
依托单位：
Yamaguchi Prefectural University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

The molecular inclusion of several environmental estrogens and other hormones with (β-, dimethy-β-, and trimethyl-β-cyclodextrins(CD) as receptor models in aqueous solution was investigated at different temperatures. The binding constants were calculated for each system imposing a 1:1 stoichiometry. Dimethyl-β-CD showed the highest binding constant among the three complexes. The fitness of the guest to the cavity of CD was suggested to affect the binding constant. Based on the temperature dependence of the binding constants at different temperatures, the entropy and enthalpy changes were calculated for the complex formation and contribution of entropy to the process was discussed. Molecular modeling studies were performed by means of Monte Carlo Simulation in order to determine the preferred complex formation of cyclodextrins and environmental estrogen molecules. The formation of the complex involves the phenyl group of the guest molecules which mainly interact with electrostatic interaction and hydrophobic interaction by van der Waals forces. Molecular mechanics(MM) calculations served to investigate the molecular inclusion. The more energetically stable complexes by inclusion with CD calculated based on semiempirical molecular orbital (MO) were obtained compared with CD and estrogen alone, respectively. The structural information about the preferred complex formation by inclusion from the MO calculations was also obtained and the results were compared with experimental data.

以环糊精(β-，Domey-β-，CD)为受体模型，在不同温度下研究了几种环境雌激素和其他激素在水溶液中的分子包合行为。计算了施加1：1化学计量比的每个体系的结合常数。在三种配合物中，二甲基-β-CD的结合常数最高。客体对Cd空腔的适合性对结合常数有影响。根据不同温度下结合常数随温度的变化关系，计算了络合物形成的熵和热变，并讨论了熵对络合物形成过程的贡献。通过蒙特卡罗模拟进行了分子模拟研究，以确定环糊精和环境雌激素分子的首选络合物形成。络合物的形成涉及客体分子的苯基，主要通过静电相互作用和范德华作用力疏水相互作用。分子力学(MM)计算用于研究分子包裹体。根据半经验分子轨道(MO)计算得到的Cd包合物比Cd和雌激素单独包合得到了能量更稳定的配合物。从分子轨道计算中还得到了包裹体优先形成络合物的结构信息，并将计算结果与实验数据进行了比较。