利用傅里叶红外光谱和共聚焦显微拉曼光谱技术,比较分析了大蒜主要功能活性成分前体蒜氨酸和甲基蒜氨酸粉末纯品的红外和拉曼谱。在3 200~2 800 cm^-1和1 700~200 cm^-1波段检测到显著的红外和拉曼吸收峰,其中蒜氨酸在3 080,1 617,1 582,1 496,1 418,1 342,1 301,919 cm^-1处有8个较强的红外吸收峰,以及在3 088,1 636,1 404,1 290,1 051,790,745,693,588 cm^-1处有9个较强的拉曼振动峰,可作为蒜氨酸的特征峰;甲基蒜氨酸在1 644,1 481,1 395,1 370,1 233,1 068,1 004,892 cm^-1处有8个较强的红外吸收峰,以及在1 644,1 310,1 073,1 011,998,893,846,702,676 cm^-1处有9个较强的拉曼振动峰,可作为甲基蒜氨酸的特征峰。蒜氨酸和同系物甲基蒜氨酸的红外及拉曼光谱具有明显差异,红外及拉曼光谱技术为蒜氨酸及其同系物的快速、 简便的分析提供了方法。
In the present study, the alliin and methiin as the precursor of the primary functional active components in garlic were tested by using Fourier transform infrared (FT-IR) spectroscopy and confocal micro-Raman spectroscopy. Significant IR and Raman absorption peaks were detected in the range of 3 200-2 800 cm^-1 and 1 700-200 cm^-1 , respectively. For alliin eight intense IR absorption peaks were observed at 3 080, 1 617, 1 582, 1 496, 1 418, 1 342, 1 301 and 919 cm^-1 , respectively, and nine strong Raman vibration peaks were assigned at 3 088, 1 636, 1 404, 1 290, 1 051, 790, 745, 693 and 588 cm^- 1, respectively, as its characteristic peaks. In parallel, for methiin eight strong IR absorption peaks were revealed at 1 644, 1 481, 1 395, 1 370, 1 233, 1 068, 1 004 and 892 cm^-1 , respectively, and nine intensive Raman vibration peaks were presented at 1 644, 1 310, 1 073, 1 011, 998, 893, 846, 702 and 676 cm^-1 , respectively, as its characteristic peaks. It is concluded that the IR and Raman spectra of alliin and its homologue, methiin, show obvious differences, and these two methods are provided for the rapid and simple analysis of alliin and its homologues.