Sanz Miguel Pablo J, Lax Patrick, Lippert Bernhard
Anorganische Chemie III, Fachbereich Chemie, Universität Dortmund, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany.
J Inorg Biochem. 2006 May;100(5-6):980-91. doi: 10.1016/j.jinorgbio.2006.02.017. Epub 2006 Mar 3.
Despite their structural similarity, Pt(dien)(1-MeC-N3) (1), Pd(dien)(1-MeC-N3) (2), and Pt(NH(3))(3)(1-MeC-N3) (3) (with dien=diethylenetriamine and 1-MeC=neutral 1-methylcytosine) behave in part markedly different at strongly alkaline pH (12-13) and at room temperature. While 1 and 2, yet not 3 show linkage isomerization from N3 to N4, deamination of the cytosine nucleobase to 1-methyluracilate occurs with 1 and 3, yet not with 2. Pathways leading to N3,N4-diplatinated 1-MeC(-) complexes (1-MeC(-)=1-methylcytosine, deprotonated at exocyclic amino group N4) have been studied at high pH by starting from 1 and 3, respectively, and adding (dien)Pt(II). It appears that initial migration of the metal entity from N3 to N4, followed by binding of the second metal to the available N3 site, is favored over sequential coordination to N3 and then N4. X-ray crystal data of 1-3 density functional theory (DFT) calculations, and NMR ((1)H, (195)Pt) data are presented.
尽管Pt(dien)(1-MeC-N3)（1）、Pd(dien)(1-MeC-N3)（2）和Pt(NH(3))(3)(1-MeC-N3)（3）（其中dien = 二乙烯三胺，1-MeC = 中性1-甲基胞嘧啶）结构相似，但在强碱性pH值（12 - 13）和室温下，它们的部分行为却显著不同。虽然1和2会发生从N3到N4的键合异构化，而3不会，但1和3会发生胞嘧啶碱基脱氨基生成1-甲基尿嘧啶，而2不会。通过分别从1和3开始，并加入(dien)Pt(II)，在高pH值下研究了生成N3,N4-双铂化（diplatinated）1-MeC(-)配合物（1-MeC(-)=1-甲基胞嘧啶，在外环氨基N4处去质子化）的途径。结果表明，相比于依次与N3和N4配位，金属实体从N3初始迁移到N4，随后第二个金属与可用的N3位点结合的方式更受青睐。文中给出了1 - 3的X射线晶体数据、密度泛函理论（DFT）计算结果以及核磁共振（(1)H、(195)Pt）数据。
