山奈酚与水的氢键作用对其抗氧化活性影响的理论研究  

The Theory Investigation of the Effect of Intermolecular Hydrogen Bond with Water on the Antioxidant Activity of Kaempferol

作　　者：祝亚云[1] 潘良军[1] 赵良容[1] 晏名勋[1] 杨昌英[1] 

机构地区：[1]三峡大学天然产物研究与利用湖北省重点实验室,宜昌443002

出　　处：《天然产物研究与开发》2013年第6期792-795,共4页Natural Product Research and Development

基　　金：湖北省自然科学基金项目(2010CDB10704)

摘　　要：本文用密度泛函理论在(RO)B3LYP/6-31G(2d,2p)水平上对山奈酚及其与水分子之间形成的氢键复合物进行结构优化,通过热力学计算研究了不同位置的酚羟基发生抽氢反应的键离解能(BDE)、质子解离反应过程的质子解离能(DPE)受分子间氢键的影响。结果表明:与H2O形成的分子间氢键会影响化合物结构,改变化合物B环与AC环的二面角,A5位酚羟基更容易发生抽氢反应和质子解离反应,此位点的BDE和DPE均明显降低,同时也降低C3位质子解离的DPE。分子间氢键的形成促使酚羟基的抽氢和质子解离反应,提高化合物抗氧化活性。Density functional theory （ DFT ） calculations, based on Becke＇ s three-parameter density functional （ B3 LYP） method using the 6-31G （2d,2p） basis set,were performed to evaluate the O-H bond dissociation energies （BDEs） and deprotonation energies （DPEs） of kaempferoland its hydrogen bond complex with one or two water molecules. The re- sults showed that the intermolecular hydrogen bond with H2O would change the conformer of kaempferol,twist the all- hydral angel between the B ring and AC ring. The BDE and DPE from A.5 -OH decreased significantly,the transfer and deprotonation of the H atom from A5-OH would be more easily compared to the single kaempferol. It was confirmed that the water around kaempferol would accelerate the hydrogen atom or proton to dissociate from phenol hydroxyl and pro- mote its antioxidant activity.

关 键 词：山奈酚 B3LYP 6-31G(2d 2p) 分子间氢键 键离解能(BDE) 去质子化能(DPE) 

分 类 号：O641.12[理学—物理化学]