NEQC: Núcleo de Estudos em Química Computacional, Departamento de Química, Universidade Federal de Juiz de Fora, Campus Universitário Martelos, 36.036-900 Juiz de Fora, MG, Brazil.
NQTCM: Núcleo de Química Teórica e Computacional de Macaé, Polo Ajuda, Instituto Multidisciplinar de Química, Centro Multidisciplinar UFRJ-Macaé, Universidade Federal do Rio de Janeiro, 27.973-545 Macaé, RJ, Brazil.
J Inorg Biochem. 2022 Nov;236:111970. doi: 10.1016/j.jinorgbio.2022.111970. Epub 2022 Aug 20.
Gold(III) complexes are promising compounds for cancer chemotherapy, whose action depends on their redox stability. In this context, the choice of ligands is crucial to adjust their reactivity and biological response. The present study addressed the effect of the gold coordination sphere on the reduction potential (E) for ten gold(III) complexes containing five or six-membered rings tridentate ligands - [Au(trident)Cl] (trident = N^N^N, C^N^N, C^C^N, C^N^C, and N^C^N). The calculated E covered a broad range of 2500 mV with the most stable complexes containing two AuC bonds (E = -1.85 V for [Au(C^C^N)Cl] - f). For complexes with one AuC bond, the N^C^N ligands stabilize the gold(III) complex more efficiently than N^N^C; however, the inclusion of the non-innocent ligand bipy (2,2'-bipyridine) in N^N portion provides an extra stabilization effect. Among the derivatives with one AuC bond, [Au(N^N^C)Cl] (N^N = bipy) (a) showed E = -1.20 V. For the complexes with N^N^N ligands, E was positive and almost constant (+0.60 V). Furthermore, the kinetics for ligand exchange reactions (Cl/HO, HO/Cys and Cl/Cys) were monitored for the most stable compounds and the energy profiles compared to the reduction pathways.
金（III）配合物是癌症化疗有前途的化合物，其作用取决于其氧化还原稳定性。在这种情况下，配体的选择对于调节其反应性和生物响应至关重要。本研究探讨了金配位球对十个含五或六元环三齿配体的金（III）配合物的还原电位（E）的影响-[Au（trident）Cl]（trident=N^N^N、C^N^N、C^C^N、C^N^C 和 N^C^N）。计算出的 E 覆盖了很宽的范围，为 2500 mV，最稳定的配合物含有两个 AuC 键（E=-1.85 V 用于[Au（C^C^N）Cl]-f）。对于含有一个 AuC 键的配合物，N^C^N 配体比 N^N^C 更有效地稳定金（III）配合物；然而，将非无辜配体 bipy（2,2'-联吡啶）包含在 N^N 部分中提供了额外的稳定化效应。在具有一个 AuC 键的衍生物中，[Au（N^N^C）Cl]（N^N=bipy）（a）表现出 E=-1.20 V。对于具有 N^N^N 配体的配合物，E 为正且几乎恒定（+0.60 V）。此外，监测了最稳定化合物的配体交换反应（Cl/HO、HO/Cys 和 Cl/Cys）的动力学，并与还原途径比较了能量曲线。
