理论探究咖啡因N_3和N_7位水解去甲基代谢机理  

Theoretical Study on the Hydrolysis Demethylation Metabolic Mechanisms of Caffeine at N_3 and N_7 Sites

作　　者：康媛[1,2] 陶婧[1,2] 陈秋[1,2] 王永婷[1,2] 张燕[1,2] 薛志宇[1,2] 陈泽琴[1,2] 

机构地区：[1]西华师范大学化学化工学院,四川南充637009 [2]西华师范大学四川省化学合成与污染控制重点实验室,四川南充637009

出　　处：《西华师范大学学报（自然科学版）》2015年第4期367-372,共6页Journal of China West Normal University(Natural Sciences)

基　　金：国家自然科学基金项目(21203153);四川省科技厅应用基础研究项目(2011JY0136);四川省教育厅重点项目(12ZA174);西华师范大学博士启动基金资助项目(11B002)

摘　　要：采用BH&HLYP/6-311++g(d,p)方法研究了咖啡因N3和N7位水解代谢机理.每个N位的水解代谢机理考察了两种可能的反应路径:分步的路径A和协同的路径B.计算结果表明:对于N3或N7位水解代谢,路径A均优于路径B;N3位水解代谢的路径A所需的活化自由能(358.8 k J·mol-1)低于N7位(363.1 k J·mol-1),因而代谢产物副黄嘌呤优于茶碱.The hydrolysis metabolic mechanisms of caffeine at N3 and N7 sites were clarified in this paper under the BH＆HLYP/6-311 ＋ ＋ g（d,p） theory. Two possible reaction pathways were identified for each N-site hydrolysis metabolic mechanism： the stepwise path A and the concert path B. The calculation results showed that path A was more favorable than paths B for both the N3- and the N7-sites hydrolysis metabolic mechanism. The activation free energy of path A involved in N3-site hydrolysis metabolic mechanism （358.8 kJ·mol^-1） was lower than that of N3-site （363.1 kJ·mol^-1 ） and the metabolite paraxanthine therefore was more favorable than theophylline.

关 键 词：咖啡因 水解 去甲基反应 密度泛函理论 BH&HLYP 

分 类 号：O643.1[理学—物理化学]