咖啡因N_1位水解去甲基反应机理的理论研究

Study on the Hydrolysis Demethylation Mechanisms of Position N_1 of Caffeine

基于密度泛函理论,利用BH&HLYP/6-311++g(d,p)方法对咖啡因N1位水解去甲基机理进行了研究.主要考察了两条反应路径,路径A为O6氢转移机理,路径B为O2氢转移机理.计算结果表明,路径A略优于路径B,但两条反应路径均需较高的活化能(大于350 kJ·mol-1),因而很难直接通过水解脱去甲基,从而强调了酶的重要催化作用.

The hydrolysis demethylation mechanisms of position N1 of caffeine were explored in this paper by density functional theory at the BH＆HLYP/6-311 ＋ ＋ g（d,p） theory of level.Two pathways were investigated.Pathways A and B involved the O6 and O2 hydrogen transfer mechanisms,respectively.The calculated results show that pathway A is slightly more favorable than pathway B.However,the two pathways both involve high activation energies more than 350 kJ mol-1.Consequently,it is unfeasible for the demethylation of position N1 of caffeine via direct hydrolysis,which emphases the important catalytic role of enzyme.