In this study, we provide the first Fourier-transform infrared absorption spectroscopy (FTIR) and Raman spectroscopy (RS) analysis of a vibrational fingerprint of erlotinib, a drug which is applied in non-small cell lung cancer therapy, in solid state and solution in different pH conditions. Additionally, the performed DFT theoretical calculations in vacuum and PCM models support the interpretation of vibrational spectra and give insight into an optimized spatial configuration of the investigated drug. The present considerations show vibrational structure of erlotinib and details of its molecular geometry. Furthermore, we discuss the pH condition where the protonated –NH⁺ and C=N⁺ forms occur and indicate the spectral changes characteristic for the erlotinib protonation. It is of great of importance to better understand biological activity of the drug and to develop new tyrosine kinase inhibitors.

中文翻译：

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厄洛替尼的振动指纹图：FTIR，RS和DFT研究

在这项研究中，我们提供了第一版傅立叶变换红外吸收光谱（FTIR）和拉曼光谱（RS）对埃洛替尼（一种用于非小细胞肺癌治疗的药物）的固态和溶液振动指纹图谱的分析在不同的pH条件下。此外，在真空和PCM模型中执行的DFT理论计算支持振动光谱的解释，并深入了解所研究药物的优化空间构型。目前的考虑表明厄洛替尼的振动结构及其分子几何结构的细节。此外，我们讨论了质子化-NH ⁺和C = N ⁺的pH条件形式发生并表明厄洛替尼质子化的光谱变化特征。更好地了解药物的生物学活性并开发新的酪氨酸激酶抑制剂非常重要。