The synthetic approaches for the preparation of trans(NO,OH)-cis(NO₂,NO₂)-[RuNO(L)₂(NO₂)₂OH], where L = ethyl nicotinate (I) and methyl nicotinate (II), are reported. The structures of the complexes are characterized by X-ray diffraction and analyzed by Hirshfeld surface analysis. Both compounds show a nitric oxide release reaction under 445 or 532 nm irradiation of dimethyl sulfoxide (DMSO) solutions, which is studied by combined ultraviolet-visible- (UV-vis), infrared- (IR), and electron paramagnetic resonance (EPR) spectroscopy and density functional theory (DFT) calculations. The charge transfer from the OH–Ru–NO chain and nitrite ligands to the antibonding orbitals of Ru–NO is responsible for the photo-cleavage of the ruthenium–nitrosyl bond. The elimination of NO leads to a side reaction, namely the protonation of the parent hydroxyl compound. The cytotoxicity and photo-induced cytotoxicity investigations of both compounds on the breast adenocarcinoma cell line MCF-7 reveal that (I) and (II) are cytotoxic with IC₅₀ values of 27.5 ± 2.8 μM and 23.3 ± 0.3 μM, respectively. Moreover, (I) shows an increase of the toxicity after light irradiation by 7 times (IC₅₀ = 4.1 ± 0.1), which makes it a prominent target for deeper biological investigations.

中文翻译：

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亚硝基钌与烟酸配位衍生物的一氧化氮释放和相关的光诱导细胞毒性

制备反式(NO,OH)-顺式(NO ₂ ,NO ₂ )-[RuNO(L) ₂ (NO ₂ ) ₂ OH]的合成方法，其中L =烟酸乙酯( I )和烟酸甲酯( II )), 被报道。配合物的结构通过 X 射线衍射表征并通过 Hirshfeld 表面分析进行分析。两种化合物在二甲基亚砜 (DMSO) 溶液的 445 或 532 nm 照射下均显示出一氧化氮释放反应，该反应通过组合紫外-可见 (UV-vis)、红外 (IR) 和电子顺磁共振 (EPR) 进行研究光谱学和密度泛函理论 (DFT) 计算。从 OH-Ru-NO 链和亚硝酸盐配体到 Ru-NO 的反键轨道的电荷转移是造成钌-亚硝基键的光裂解的原因。NO 的消除导致副反应，即母体羟基化合物的质子化。两种化合物对乳腺癌细胞系 MCF-7 的细胞毒性和光诱导细胞毒性研究表明（I ) 和 ( II ) 具有细胞毒性，IC ₅₀值分别为 27.5 ± 2.8 μM 和 23.3 ± 0.3 μM。此外，( I ) 显示光照射后毒性增加 7 倍 (IC ₅₀ = 4.1 ± 0.1)，这使其成为更深入的生物学研究的突出目标。