Hua Rui, Sun Su-Qin, Zhou Qun, Noda Isao, Wang Bao-Qin
Department of Chemistry, Tsinghua University, Beijing 100084, China.
J Pharm Biomed Anal. 2003 Sep 19;33(2):199-209. doi: 10.1016/s0731-7085(03)00253-x.
Fritillaria is a traditional Chinese herbal medicine for eliminating phlegm and relieving a cough with a long history in China and some other Asian countries. The objective of this study is to develop a nondestructive and accurate method to discriminate Fritillaria of different geographical origins, which is a troublesome work by existing analytical methods. We conducted a systematic study on five kinds of Fritillaria by Fourier transform infrared spectroscopy, second derivative infrared spectroscopy, and two-dimensional (2D) correlation infrared spectroscopy under thermal perturbation. Because Fritillaria consist of a large amount of starch, the conventional IR spectra of different Fritillaria only have very limited spectral feature differences. Based on these differences, we can separate different Fritillaria to a limited extent, but this method was deemed not very practical. The second derivative IR spectra of Fritillaria could enhance spectrum resolution, amplify the differences between the IR spectra of different Fritillaria, and provide some dissimilarity in their starch content, when compared with the spectrum of pure starch. Finally, we applied thermal perturbation to Fritillaria and analyzed the resulting spectra by the 2D correlation method to distinguish different Fritillaria easily and clearly. The distinction of very similar Fritillaria was possible because the spectral resolution was greatly enhanced by the 2D correlation spectroscopy. In addition, with the dynamic information of molecular structure provided by 2D correlation IR spectra, we studied the differences in the stability of active components of Fritillaria. The differences embodied mainly on the intensity ratio of the auto-peak at 985 cm(-1) and other auto-peaks. The 2D correlation IR spectroscopy (2D IR) of Fritillaria can be a new and powerful method to discriminate Fritillaria.
川贝母是一种传统的中药材，在中国和其他一些亚洲国家有着悠久的化痰止咳历史。本研究的目的是开发一种无损且准确的方法来鉴别不同地理来源的川贝母，而现有的分析方法在这项工作上存在困难。我们通过傅里叶变换红外光谱、二阶导数红外光谱以及热扰动下的二维（2D）相关红外光谱，对五种川贝母进行了系统研究。由于川贝母含有大量淀粉，不同川贝母的常规红外光谱仅具有非常有限的光谱特征差异。基于这些差异，我们可以在一定程度上区分不同的川贝母，但这种方法被认为不太实用。川贝母的二阶导数红外光谱可以提高光谱分辨率，放大不同川贝母红外光谱之间的差异，并与纯淀粉光谱相比，显示出它们在淀粉含量上的一些不同。最后，我们对川贝母施加热扰动，并通过二维相关方法分析所得光谱，从而轻松且清晰地区分不同的川贝母。二维相关光谱极大地提高了光谱分辨率，使得区分非常相似的川贝母成为可能。此外利用二维相关红外光谱提供的分子结构动态信息，我们研究了川贝母活性成分稳定性的差异。这些差异主要体现在985 cm⁻¹处的自动峰与其他自动峰的强度比上。川贝母的二维相关红外光谱（2D IR）可以成为鉴别川贝母的一种新的有力方法。
