Kareru P G, Keriko J M, Gachanja A N, Kenji G M
Department of Chemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. BOX 62000-00200, Nairobi, Kenya.
Afr J Tradit Complement Altern Med. 2007 Oct 27;5(1):56-60. doi: 10.4314/ajtcam.v5i1.31257.
Direct detection of saponins in medicinal plants using Fourier Transform Infrared (FTIR) spectroscopy is reported in this paper. Crude dry plant powders were mixed with potassium bromide (KBr) powder and compressed to a thin pellet for infrared examination. FTIR spectra of the test samples showed -OH, -C=O, C-H, and C=C absorptions characteristic of oleanane triterpenoid saponins. The C-O-C absorptions indicated glycoside linkages to the sapogenins. Phytochemical analysis confirmed the presence of saponins in the tested specimens. Entada leptostachya was used as a reference sample. Dry plant powder was extracted sequentially with hexane, dichloromethane, ethyl acetate and methanol. FTIR spectra of the reference sample powder and its organic solvent extracts showed characteristic saponin absorption peaks. These results indicated that direct detection of saponins in medicinal plants was possible by infrared analysis. Lengthy exhaustive chemical analyses necessary for detection of saponins could be avoided.
本文报道了利用傅里叶变换红外（FTIR）光谱法直接检测药用植物中的皂苷。将干燥的植物粗粉与溴化钾（KBr）粉末混合，压制成薄片进行红外检测。测试样品的FTIR光谱显示出齐墩果烷三萜皂苷特有的-OH、-C=O、C-H和C=C吸收峰。C-O-C吸收峰表明存在与皂苷元的糖苷键。植物化学分析证实了测试样品中存在皂苷。将藤合欢作为参考样品。干燥的植物粉末依次用己烷、二氯甲烷、乙酸乙酯和甲醇进行提取。参考样品粉末及其有机溶剂提取物的FTIR光谱显示出特征性的皂苷吸收峰。这些结果表明，通过红外分析可以直接检测药用植物中的皂苷。可以避免检测皂苷所需的冗长繁琐的化学分析。
