锝化学研究  Ⅵ.~(99)Tc~m-HM-PAO异构体稳定性的研究

STABILITY OF ISOMERS OF ~(99)c~m-HM-PAO BASED ON CNDO/2 METHOD

摘要: 根据~(99)Tc标记HM-PAO的晶体结构数据,采用三种不同判断尺度对~(99)Tc~m-HM-PAO异构体进行模拟计算与构象分析。可看出这种向心配体配合物存在三种(d、l-,meso 1,meso 2)不同立体结构,找到了影响该类异构体稳定性的本质因素,探讨了d、l-CB-PAO稳定异构体的立体构型,验证了前文提出的物理模型与计算方法的可靠性,为促进药物设计和搞清有关Tc放射性药物脑代动力学的立体构象打下基础。

Abstract: Formation energy,total energy of system and net charge of isomers of 99Tcm-HM-PAO have been calculated by CNDO/2 method. The computed results indicate that the order of stability is meso 2-HM-PAO>d,l-HM-PAO> meso 1-HM-PAO. After cyclation of d,l -HM-PAO, the calculated results show that stability of d,l -CB-PAO is increased rapidly. This study reveals structural features that may be employed to account for disparate pharmacokinetics of the meso and d,l -HM-PAO 99Tcm-radiophar-maceuticals.