Probing key coordination interactions: configurationally restricted metal activated CXCR4 antagonists
作者:Graeme McRobbie、Gina C. Valks、Christopher J. Empson、Abid Khan、Jon D. Silversides、Christophe Pannecouque、Erik De Clercq、Steven G. Fiddy、Adam J. Bridgeman、Nigel A. Young、Stephen J. Archibald
DOI:10.1039/b705800d
日期:——
The syntheses of configurationally restricted mono- and bis-macrocyclic copper(II) perchlorate complexes (copper(II) 5-benzyl-1,5,8,12-tetraazabicyclo[10.2.2]hexadecane and dicopper(II) 5,5′-[1,4-phenylenebis(methylene)]-bis(1,5,8,12-tetraazabicyclo[10.2.2]hexadecane)) are reported and the X-ray structure of the copper(II) mono-macrocyclic complex has been determined. EXAFS studies on the bis-macrocyclic species in aqueous solution show that the copper coordination spheres are essentially identical to the solid state structure, and do not vary in the presence of 20 equivalents of sodium acetate per metal centre. DFT calculations were carried out at the BP86/TZP level to determine the nature of potential binding interactions with CXCR4 aspartate residues. The alkylated single macrocyclic compound was modelled with an acetate included to represent the aspartate residue, demonstrating that the predicted macrocycle configuration has the lowest energy and the acetate interaction is effectively monodentate giving a distorted trigonal bipyramidal geometry at the copper centre. In vitro anti-HIV infection assays show that the configurationally restricted dicopper(II) complex is more active (average EC50 = 0.026 μM against HIV-1) than the non-constrained dicopper(II) 1,1′-[1,4-phenylenebis(methylene)]-bis(1,4,8,11-tetraazacyclotetradecane) (average EC50 = 0.047 μM against HIV-1) although it is an order of magnitude less active than the configurationally restricted dizinc(II) complex.
合成了构型受限的单高氯酸铜(II)和双高氯酸铜(II)高环配合物(5-苄基-1,5,8,12-四氮杂双环[10.2.2]十六烷和 5,5′-[1,4-亚苯基双(亚甲基)]-双(1,5,8,12-四氮杂双环[10.2.2]十六烷)二氯化铜(II),并确定了铜(II)单高环配合物的 X 射线结构。对水溶液中的双大环物种进行的 EXAFS 研究表明,铜配位球与固态结构基本相同,并且在每个金属中心存在 20 个等量的醋酸钠时也不会发生变化。我们在 BP86/TZP 水平上进行了 DFT 计算,以确定与 CXCR4 天门冬氨酸残基的潜在结合相互作用的性质。对烷基化的单一大环化合物进行了建模,并加入了代表天冬氨酸残基的醋酸盐,结果表明预测的大环构型具有最低的能量,醋酸盐的相互作用实际上是单价的,从而在铜中心形成了扭曲的三叉双锥几何形状。体外抗艾滋病毒感染试验表明,构型受限的二氯化铜(II)复合物活性更高(平均 EC50 = 0.0.047 μM),但其活性比构型受限的二锌(II)复合物低一个数量级。