Computer simulation of nickel in blood-plasma following the in vitro investigations of complex formation chemistry with polyamine(amide) ligands
作者:Edmund T. Nomkoko、Graham E. Jackson、Bandile S. Nakani、Susan A. Bourne
DOI:10.1039/b405756m
日期:——
In- and out-of-cell potentiometric techniques have been used to determine the formation constants for nickel(II) with 3,3,9,9-tetramethyl-4,8-diazaundecane-2,10-dione dioxime (L1), N,N′-bis(2-hydroxyiminopropionyl)propane-1,3-diamine (L2) and 1,15-bis(N,N-dimethyl)-5,11-dioxo-8-(N-benzyl)-1,4,8,12,15-pentaazapentadecane (L3) at 25 °C and an ionic strength of 0.15 mol dm−3. Nickel(II) forms stable complexes with L1 and L2 where square-planar [NiLH−1] and [NiLH−2] species predominate under alkaline conditions. The square-planar coordination of nickel by L1 has been confirmed by a single-crystal X-ray structure, UV/Vis spectrometry and molecular mechanics calculations of the [NiL1H−1] complex. The introduction of a third amine group into L3 dramatically decreases the ligand's ability to complex Ni(II). This results from a change in structure of the complex which decreases the ability of the metal ion to promote the dissociation of the amide protons. Using a model of blood plasma, the high binding ability of L1 towards Ni(II) is calculated to decrease the mobilisation of Cu(II) in plasma by approximately 65%. [CuL1H−1] is currently under investigation as an anti-inflammatory agent.
使用电池内和电池外电位测定技术确定了镍(II)与 3,3,9,9-四甲基-4,8-二氮杂十一烷-2,10-二酮二氧肟(L1)、N、N′-双(2-羟基亚氨基丙酰基)丙烷-1,3-二胺(L2) 和 1,15-双(N,N-二甲基)-5,11-二氧代-8-(N-苄基)-1,4,8,12,15-五氮杂十烷(L3)在 25 °C 和离子强度为 0.15 摩尔 dm-3。镍(II)与 L1 和 L2 形成稳定的配合物,其中方平面 [NiLH-1] 和 [NiLH-2] 物种在碱性条件下占主导地位。单晶 X 射线结构、紫外/可见光谱和 [NiL1H-1] 复合物的分子力学计算证实了 L1 对镍的方平面配位。在 L3 中引入第三个胺基后,配体与 Ni(II)的络合能力大大降低。这是因为络合物的结构发生了变化,降低了金属离子促进酰胺质子解离的能力。利用血浆模型计算得出,L1 与 Ni(II)的高结合能力可将血浆中铜(II)的迁移率降低约 65%。[CuL1H-1]目前正在作为一种抗炎剂进行研究。