The role of drug N‐acetylcysteine (NAC) in preventing contrast‐induced nephropathy (CIN) and kidney diseases has been investigated with the help of in vitro Raman spectroscopy and density functional theory (DFT). Renal dysfunction or kidney failure is diagnosed by an increase in serum creatinine (CRN). The exposure to contrast agents during angiography also causes an increase in serum CRN, a condition termed as CIN. NAC is given to such patients, as it is known to prevent the toxic effect of CRN, although its mechanism of action is not clearly known till date. In the present study, we have studied the interaction between CRN and NAC and tried to detect the formation of a stable complex between the two by analyzing the in vitro Raman spectra of aqueous solutions of CRN and NAC mixed in different molar ratios. From the Raman spectral analysis, it is observed that a stable complex is formed at 1:1 molar ratio of CRN and NAC. This complex has been synthesized in the laboratory, and upon drying, it is transparent, gel‐like in appearance, and slightly yellowish in color. The complex is hygroscopic and has much better water solubility than CRN. Fourier‐transform infrared (FT‐IR) and Raman spectral analyses of the synthesized complex show the structural changes taking place because of complexation and provide proof that the complex is stable at room temperature. DFT‐based studies on a number of plausible structures of the complex have also been done to determine the most stable structure of the complex, and the mechanism of its formation has been explored by transition‐state calculations. This study highlights the effective role of NAC in reducing the toxic effect of CRN as the water‐soluble complex of CRN, and NAC is likely to be removed through urine.

中文翻译：

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通过N-乙酰半胱氨酸减弱肌酐水平的升高：拉曼光谱和基于密度泛函理论的水溶液体外络合监测

药物N的作用在体外拉曼光谱和密度泛函理论（DFT）的帮助下，对乙酰半胱氨酸（NAC）预防对比剂诱发的肾病（CIN）和肾脏疾病进行了研究。血清肌酐（CRN）升高可诊断为肾功能不全或肾衰竭。血管造影期间暴露于造影剂也会引起血清CRN升高，这种情况称为CIN。尽管已知NAC可以预防CRN的毒性作用，但仍可将其用于此类患者，尽管迄今为止尚不清楚其作用机理。在本研究中，我们研究了CRN和NAC之间的相互作用，并试图通过分析以不同摩尔比混合的CRN和NAC水溶液的体外拉曼光谱来检测两者之间稳定的络合物的形成。根据拉曼光谱分析，观察到在CRN和NAC摩尔比为1：1时形成稳定的络合物。该复合物是在实验室合成的，干燥后透明，呈凝胶状，颜色略带黄色。该复合物具有吸湿性，并且比CRN具有更好的水溶性。合成复合物的傅立叶变换红外光谱（FT-IR）和拉曼光谱分析显示，由于络合作用而发生的结构变化，并提供了证明该络合物在室温下稳定的证据。也已经对复合物的许多可能结构进行了基于DFT的研究，以确定复合物的最稳定结构，并通过过渡态计算探索了其形成机理。