采用溴化钾压片法及傅里叶变换红外光谱技术对中药三七(Panax notoginseng)的剪口、 主根、 筋条、 绒根等不同部位以及表皮、 韧皮部、 形成层和木部等不同组织的红外光谱及其二阶导数谱进行了研究。 三七不同部位及组织红外光谱的整体峰形相似; 在3 400, 2 930, 1 645, 1 155, 1 080和1 020 cm-1附近有淀粉的特征吸收峰, 其主体成分均为淀粉。 但各部位和组织的红外光谱及其特征性化学成分有差异。 剪口在1 077和1 152 cm-1处峰的强度比大于其他部位, 皂苷的含量最高。 剪口及其表皮在1 317和780 cm-1特征峰明显, 含草酸钙; 并且剪口表皮中草酸钙的含量比剪口中的含量高。 绒根在1 384和825 cm-1处有硝酸盐的特征峰, 说明绒根富含硝酸盐类成分。 主根表皮在2 926, 2 854和1 740 cm-1处的吸收峰较强, 酯类成分的含量较高。 形成层的红外光谱中酰胺Ⅰ带和酰胺Ⅱ带峰明显, 富含蛋白质。 由此可见, 三七不同部位和组织的红外光谱及其二阶导数谱各有特征, 不仅揭示了整体化学成分, 还能提供有机大分子、 无机小分子等特征性成分信息。 红外光谱可用于三七及其不同部位和组织的准确、 快速鉴别及质量评价。

The techniques of Fourier transform infrared (FTIR) spectroscopy were applied to analyze the different parts and tissues of Panax Notoginseng (Sanqi, SQ), i.e. rhizome, main root, rootlet, fibrous root, xylem, cambium, phloem and epidermis. Both the FTIR spectra and second derivative spectra of these various parts and tissues of SQ samples were found to be similar. Their dominant component is starch resulting from the characteristic peaks of starch observed at 3 400, 2 930, 1 645, 1 155, 1 080 and 1 020 cm-1 on the spectra of all these SQ samples. However, the varieties of peaks were found on the spectra among these specific samples. The rhizome contains more saponins than others on the basis of the largest ratio of the peak intensity at 1 077 cm-1 to that at 1 152 cm-1. The peaks located at 1 317 and 780 cm-1 on the FTIR spectra of the rhizome and its epidermis indicate that the two parts of SQ samples contain large amount of calcium oxalate, and its content in the latter is relative larger than that in former. The fibrous root contains much amount of nitrate owing to the obvious characteristic peaks at 1 384 and 831 cm-1. For the difference among the various tissues of SQ samples, the peaks at 2 926, 2 854 and 1 740 cm-1 on the FTIR spectra of epidermis is the strongest among the various tissues of main root indicating the largest amount of esters in epidermis. Protein was also found in the cambium of the main root based on the relative strong peaks of amide Ⅰ and Ⅱ band at 1 641 and 1 541 cm-1, respectively. The results indicate that FTIR spectra with its second derivative spectra can show the characteristic of the various parts and tissues of SQ samples in both the holistic chemical constituents and specific chemical components, including organic macromolecule compounds and small inorganic molecule compounds. FTIR spectroscopy is a useful analytical method for the genuine and rapid identification and quality assessment of SQ samples.