当归及其提取物的红外光谱鉴别

Rapid Analysis of Angelica and Its Extracts by Infrared Spectroscopy

目的:采用红外光谱法对当归及其提取物的化学成分进行分析,观察药材化学成分的整体变化规律,为药材整体质量评价体系的建立提供一定理论依据。方法:用水蒸气蒸馏再水提的方法提取当归的化学成分,采用傅里叶红外光谱法(FT-IR)及二阶导数谱分析鉴定当归原药材、当归不同提取物化学成分的红外光谱特征。结果:(1)当归为高蔗糖类药材。(2)当归粉末、乙醚提取物皆于1740 cm-1左右(羰基伸缩振动吸收峰)有较强、较宽的吸收,而当归水提物及药渣水提物中的羰基吸收峰不明显,说明当归水提物中主要为多糖类成分。而蒸馏液的乙醚提取物中水溶性成分较少,基本为内酯类成分。(3)不同提取方法对当归中化学成分的含量有一定的影响,这种先蒸馏再水提药渣的优化工艺相对于直接用水提取,能得到更多的脂溶性成分,还能提取出较多的当归多糖等水溶性成分,扩宽了用药范围,避免了药材浪费。结论:红外光谱分析法能快速、简便地鉴别当归及其提取物的化学成分,优化了药材的提取工艺,为中药当归鉴定和制定质量标准提供一种新的方法和手段。

Objective： Using infrared spectroscopy to analyze the chemical composition of Angelica and observe the overall variation of the chemical composition of herbs to provide a theoretical basis for the establishment of medicinal overall quality evaluation system. Methods： The chemical composition of Angelica was extracted by steam distillation and then water extraction. Fourier transform- infrared spectroscopy（ FT- IR） and the second derivative infrared spectroscopy（ SD- IR） could be applicable to analyze and identify Angelica raw materials and its different extractions. Results：（ 1） Angelica contains large amounts of sucrose.（ 2） The powder and ether extraction around at 1740 cm- 1（ carbonyl stretching vibration absorption peak） has a strong,broad absorption while the absorption peak was less obvious in water extraction and water extraction of the distillation residue. So the main components of Angelica water extraction are polysaccharides. But the ether extraction contains less water- soluble constituents and more lactones ingredients.（ 3） Different extraction methods have some influence on the content of the chemical composition of Angelica. Compared to direct water extraction,the process optimization of water extraction of the distillation residue can not only get more liposoluble constituents,but also get more Angelica polysaccharides and other water- soluble constituents. This method could widen the scope of medication and avoid the waste of herbs. Conclusion： Infrared spectroscopy can be a quick and easy identification of the chemical composition of Angelica and its extractions,optimizing the extraction process of herbs and providing a new method and means for the identification and development quality standards of Angelica.