Mechanistic Study on the Monofunctional Binding of Hydrolysis Products of Non-planar Heterocyclic Complexes Trans-[PtCl_2NH_3(piperidine)] and Trans-[PtCl_2(piperidine)_2] to DNA Purine Bases  

作　　者：陈鋆晖 周立新 

机构地区：[1]Department of Chemistry,Jinan University

出　　处：《Chinese Journal of Structural Chemistry》2010年第10期1536-1546,共11页结构化学（英文）

基　　金：supported from the National Natural Science Foundation of China (No. 20971056)

摘　　要：The monofunctional substitution reactions between trans-[PtCl（H2O）（NH3）（pip）]＋,trans-[Pt（H2O）2（NH3）（pip）]2＋,trans-[PtCl（H2O）（pip）2]＋,trans-[Pt（H2O）2（pip）2]2＋ （pip = piperidine） and adenine/guanine nucleotides are explored by using B3LYP hybrid functional and IEF-PCM salvation models. For the trans-[Pt（H2O）2（NH3）（pip）]2＋ and trans-[PtCl（H2O）（NH3）（pip）]＋ complexes,the computed barrier heights in aqueous solution are 13.5/13.5 and 11.6/11.6 kcal/mol from trans-Pt-chloroaqua complex to trans/cis-monoadduct for adenine and guanine,and the corresponding values are 20.7/20.7 and 18.8/18.8 kcal/mol from trans-Pt-diaqua complex to trans/cis-monoadduct for adenine and guanine,respectively. For trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋,the corresponding values are 21.5/21.3 and 19.4/19.4 kcal/mol,and 26.0/26.0 and 20.7/20.8 kal/mol for adenine and guanine,respectively. Our calculations demonstrate that the barrier heights of chloroaqua are lower than the corresponding values of diaqua for adenine and guanine. In addition,the free energies of activation for guanine in aqueous solution are all smaller than that for adenine,which predicts a preference of 1.9 kcal/mol when trans-[PtCl（H2O）（NH3）（pip）]＋ and trans-[Pt（H2O）2（NH3）（pip）]2＋ are the active agents and ～1.9 and ～ 5.3 kcal/mol when trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋ are the active agents,respectively. For the reaction of trans-Pt-chloroaqua （or diaqua） to cis-monoadduct,we obtain the same transition-state structure as from the reaction of trans-Pt-chloroaqua （or diaqua） to trans-monoadduct,which seems that the trans-Pt-chloroaqua （or diaqua） complex can generate trans-or cis-monoadduct via the same transition-state.The monofunctional substitution reactions between trans-[PtCl（H2O）（NH3）（pip）]＋,trans-[Pt（H2O）2（NH3）（pip）]2＋,trans-[PtCl（H2O）（pip）2]＋,trans-[Pt（H2O）2（pip）2]2＋ （pip = piperidine） and adenine/guanine nucleotides are explored by using B3LYP hybrid functional and IEF-PCM salvation models. For the trans-[Pt（H2O）2（NH3）（pip）]2＋ and trans-[PtCl（H2O）（NH3）（pip）]＋ complexes,the computed barrier heights in aqueous solution are 13.5/13.5 and 11.6/11.6 kcal/mol from trans-Pt-chloroaqua complex to trans/cis-monoadduct for adenine and guanine,and the corresponding values are 20.7/20.7 and 18.8/18.8 kcal/mol from trans-Pt-diaqua complex to trans/cis-monoadduct for adenine and guanine,respectively. For trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋,the corresponding values are 21.5/21.3 and 19.4/19.4 kcal/mol,and 26.0/26.0 and 20.7/20.8 kal/mol for adenine and guanine,respectively. Our calculations demonstrate that the barrier heights of chloroaqua are lower than the corresponding values of diaqua for adenine and guanine. In addition,the free energies of activation for guanine in aqueous solution are all smaller than that for adenine,which predicts a preference of 1.9 kcal/mol when trans-[PtCl（H2O）（NH3）（pip）]＋ and trans-[Pt（H2O）2（NH3）（pip）]2＋ are the active agents and ～1.9 and ～ 5.3 kcal/mol when trans-[PtCl（H2O）（pip）2]＋ and trans-[Pt（H2O）2（pip）2]2＋ are the active agents,respectively. For the reaction of trans-Pt-chloroaqua （or diaqua） to cis-monoadduct,we obtain the same transition-state structure as from the reaction of trans-Pt-chloroaqua （or diaqua） to trans-monoadduct,which seems that the trans-Pt-chloroaqua （or diaqua） complex can generate trans-or cis-monoadduct via the same transition-state.

关 键 词：DFT trans-[PtCl2NH3（piperidine）] and trans-[PtCl2（piperidine）2] DNA bases transition state activation energy 

分 类 号：Q523[生物学—生物化学]