鬼针草主要化学成分与水分子间氢键的理论研究

摘要

研究降糖中药中有效化学成分与水分子间的相互作用,尤其是氢键的作用,探讨其对药物分子几何结构和性质的影响,因为药物分子在人体中起作用的同时,H2O是必须参与其中的.在B3LYP水平上用Gaussian09程序包分别优化了H2O,降糖中药鬼针草(一种用途广泛的具有降血糖功效的传统中药)中有效化学成分Okanin(奥卡宁)、Luteolin(木犀草素)、Quercitin(槲皮素)、6,7,3'4'-tetrahydroxy auroe(6,7,3'4'-四羟基橙酮)分子与H2O相互作用后的几何构型,得到相应的几何结构优化参数、偶极矩、电荷分布等,并在同一水平上计算了相互作用能,我们首先分析了电荷分布知氢键形成的电场环境,然后分析几何参数变化知氢键的特点,最后分析相互作用能知氢键的稳定性.结果表明,此四种分子均可与水分子形成稳定的氢键(其氢键的键长分别为Luteolin-H2O 1.936(A),Okanin-H2O 1.805(A),Quercitin-H2O 1.827 (A),6,7,3'4'-tetrahydroxy auroe-H2O 1.812(A),其中Luteolin(木犀草素)分子和Quercitin(槲皮素)分子与水形成氢键的键能最大,是因为这两个药物分子的邻位羟基均有与水分子形成氢键的倾向.%The interaction between the chemical components of hypoglycemic effective traditional Chinese medicine and H2 O especially the hydrogen bond has been investigated theoretically to discuss the effect of the interaction to medicine molecular geometric structures and properties,because H2 O must be involved in the process when the medicine molecules play a role in the body.Gaussian 09 program package was employed to optimize the geometric structures of H2 O,effective chemical components in Bidens pilosa L.(a kind of widely used hypoglycemic effective traditional Chinese medicine) luteolin,okanin,quercitin and 6,7,3'4'-tetrahydroxy auroe and complexes between them and H2 O on B3 LYP level,and the geometric parameters,dipole moment,charge distribution and the interaction energy were obtained at the same computational level.In addition,the charge distribution was firstly analyzed to know the electronic environment of hydrogen bond,then the geometrical parameters were analyzed to know the characteristic of hydrogen bonds and the interaction energy to know the stability of hydrogen bonds along with the conclusion.It turned out that all the four molecules selected herein can form stable hydrogen bond with H2 O,and at the same time the charge distribution and geometrical parameters of medicine molecules changed under the effect of hydrogen bonds,among which the hydrogen bond length of luteolinH2O is 1.936 (A),Okanin-H2O is 1.805 (A),Quercitin-H2O is 1.827 (A),and 6,7,3'4'-tetrahydroxy auroe-H2O is 1.812 (A),and the bond energy values of luteolin and quercitin between H2O are the maximum ones because both the two adjacent hydroxyls of the two medicine molecules are tending to form hydrogen bond with H2O.