The Raman Active Vibrational Modes of Anthraquinones
The Raman Active Vibrational Modes of Anthraquinones
复制标题
蒽醌类化合物的拉曼主动振动模式
DOI：
10.1089/ast.2021.0170
复制
发表时间：
2022
期刊：
影响因子：
4.2
通讯作者：
Hafner, Jason H.
中科院分区：
文献类型：
--
作者：
Simeral, Mathieu L.;Hafner, Jason H.
蒽醌类化合物是一类具有良好生物活性和光学性质的天然产物。一种被称为parietin的蒽醌是由极端微生物产生的，以防止太阳紫外线B辐射，因此它是天体生物学中潜在的生物标记。现在用于太空环境的拉曼光谱学可以根据分子振动来探测诸如parietin之类的分子。在这项研究中，我们证明了时间依赖密度泛函理论（TDDFT）可以准确地计算出三种二羟基蒽醌：大黄素、大黄素和大黄酚的拉曼光谱。通过计算光谱与实测拉曼光谱的比较，确定了10种振动模式。描述了这些融合环振动的详细分子运动，并强调了所有三种分子共有的振动模式。除粉末光谱外，本文还报道了从产生parietin的地衣xanthoria parietina的菌体中进行的拉曼测量，结果与parietin粉末和计算的拉曼光谱非常吻合。这些结果表明，TDDFT计算可以在寻找地球外生物有机物质的光谱分析中做出重大贡献。
Anthraquinones are a family of natural products with useful bioactivity and optical properties. An anthraquinone called parietin is produced by extremophiles to protect against solar ultraviolet B radiation, so it is a potential biosignature in astrobiology. Raman spectroscopy, which is now used in space environments, can detect molecules such as parietin based on molecular vibrations. In this study, we show that time-dependent density functional theory (TDDFT) can accurately calculate the Raman spectra of three dihydroxyanthraquinones: parietin, emodin, and chrysophanol. By comparing calculated spectra to measured Raman spectra from purified powders, 10 vibrational modes are identified. The detailed molecular motions of these fused ring vibrations are described, and vibrations modes that are common to all three molecules are highlighted. In addition to powder spectra, Raman measurements from the thallus ofXanthoria parietina,a lichen that produces parietin, are reported, with excellent agreement to both the parietin powder and calculated Raman spectra. These results show that TDDFT calculations could make significant contributions to spectral analysis in the search for biotic organic materials beyond Earth.