Organometallic rhodium(III) complexes with curcuminoid ligands attracted considerable attention in biological‐related fields and the variation of curcuminoid ligands may regulate the biological activity of these organometallic rhodium(III) complexes. To deeply evaluate the biological influences of these complexes, the binding interactions between three rhodium(III) complexes with curcuminoid ligands and human serum albumin (HSA) were comparably investigated by spectroscopic and electrochemical techniques. The results suggested that the intrinsic fluorescence of HSA was quenched by three complexes through static fluorescence quenching mode. Three complexes bonded with Sudlow's site I of HSA to form ground‐state compounds under the binding forces of van der Waals interactions, hydrogen bonds formation, and protonation. Finally, the native conformational structure and the thermal stability of HSA were all changed. Space steric hindrance of complexes took part in the differences of the fluorescence quenching processes, and the chemical polarity of the complexes played a vital role in the variations of the structure and biological activity of HSA. These results illustrated the molecular interactions between protein and organometallic rhodium(III) complexes with curcuminoid ligands, offering new insight about the prospective applications of analogical rhodium(III) complexes in biomedicine areas.

中文翻译：

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三种有机金属铑 (III) 配合物与类姜黄素配体和人血清白蛋白之间结合相互作用的比较研究。

具有类姜黄素配体的有机金属铑(III)配合物在生物相关领域引起了广泛关注，类姜黄素配体的变化可能调节这些有机金属铑(III)配合物的生物活性。为了深入评估这些配合物的生物学影响，通过光谱和电化学技术比较研究了三种铑 (III) 配合物与类姜黄素配体和人血清白蛋白 (HSA) 之间的结合相互作用。结果表明，三种配合物通过静态荧光猝灭方式猝灭了HSA的固有荧光。与 Sudlow 的站点I结合的三个复合体HSA 在范德华相互作用、氢键形成和质子化的结合力下形成基态化合物。最后，HSA的天然构象结构和热稳定性都发生了变化。配合物的空间位阻参与了荧光猝灭过程的差异，配合物的化学极性对HSA的结构和生物活性的变化起着至关重要的作用。这些结果说明了蛋白质和有机金属铑 (III) 配合物与姜黄素配体之间的分子相互作用，为类似的铑 (III) 配合物在生物医学领域的前瞻性应用提供了新的见解。