We report the synthesis, characterization, and biological activity of Ir^I complexes with triazole‐ (NNHC) and thiazole‐based (NSHC) N‐heterocyclic carbene ligands. Starting from the dimeric [Ir(COD)Cl]₂, we obtained complexes of composition Ir(COD)(NNHC)Cl (4a), Ir(COD)(NNHC)X (4b: X = Cl; 4bBr: X = Br), [Ir(COD)(NNHC)(NHC)]I (5a), [Ir(COD)(NSHC)₂]Cl (6a), and [Ir(COD)(NSHC)(NNHC)]Cl (6b) by adaptation of established synthetic methods for metal–NHC complexes. Their interactions with model proteins cytochrome c and lysozyme, as well as with the oligonucleotide hexamer (CG)₃ (ODN1), were studied. Although most complexes did not show any strong interactions with these biomolecules, all complexes were active against HT‐29 and MCF‐7 cancerous cells, with IC₅₀ values ranging between 1 and 60 µm. The most active compounds were the cationic bis(carbene) derivatives 5 and 6. All compounds generated high levels of reactive oxygen species (ROS) after incubation for 48 h in MCF‐7 cells, possibly suggesting a redox‐mediated mechanism of action. Interestingly, there were distinctive differences in the superoxide/(total ROS) ratios induced by the different groups of compounds.

中文翻译：

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铱（I）–NHC抗癌药物候选物的合成及作用方式研究

我们报告了具有三唑（NNHC）和噻唑基（NSHC）N杂环卡宾配体的Ir ^I配合物的合成，表征和生物学活性。从二聚体[Ir（COD）Cl] _2开始，我们得到了组成为Ir（COD）（NNHC）Cl（4a），Ir（COD）（NNHC）X（4b：X = Cl; 4bBr：X = Br的配合物），[Ir（COD）（NNHC）（NHC）] I（5a），[Ir（COD）（NSHC）₂ ] Cl（6a）和[Ir（COD）（NSHC）（NNHC）] Cl（6b）），通过采用已建立的金属-NHC络合物的合成方法。它们与模型蛋白细胞色素c和溶菌酶以及寡核苷酸六聚体（CG）_3的相互作用（ODN1），进行了研究。尽管大多数复合物与这些生物分子之间均未显示出任何强相互作用，但所有复合物均具有抗HT-29和MCF-7癌细胞的活性，IC ₅₀值为1至60 µm。活性最高的化合物是阳离子双（卡宾）衍生物5和6。在MCF-7细胞中孵育48小时后，所有化合物均产生高水平的活性氧（ROS），这可能暗示了氧化还原介导的作用机制。有趣的是，由不同组的化合物引起的超氧化物/（总ROS）之比存在显着差异。