Cieśla Lukasz, Waksmundzka-Hajnos Monika
Department of Inorganic Chemistry, Medical University, 20-081 Lublin, Poland.
J Chromatogr A. 2009 Feb 13;1216(7):1035-52. doi: 10.1016/j.chroma.2008.12.057. Epub 2008 Dec 27.
Drugs, derived from medicinal plants, have been enjoying a renaissance in the last years. It is due to a great pharmacological potential of herbal drugs, as many natural compounds have been found to exhibit biological activity of wide spectrum. The introduction of whole plants, plant extracts, or isolated natural compounds has led to the need to create the analytical methods suitable for their analysis. The identification of isolated substances is relatively an easy task, but the analysis of plant extracts causes a lot of problems, as they are usually very complex mixtures. Chromatographic methods are one of the most popular techniques applied in the analysis of natural mixtures. Unfortunately the separation power of traditional, one-dimensional techniques, is usually inadequate for separation of more complex samples. In such a case the use of multidimensional chromatography is advised. Planar chromatography gives the possibility of performing two-dimensional separations with the use of one adsorbent with two different eluents or by using bilayer plates or graft thin-layer chromatography (TLC) technique; combinations of different multidimensional techniques are also possible. In this paper, multidimensional planar chromatographic methods, commonly applied in the analysis of natural compounds, were reviewed. A detailed information is given on the methodology of performing two-dimensional separations on one adsorbent, on bilayer plates, with the use of graft TLC and hyphenated methods. General aspects of multidimensionality in liquid chromatography are also described. Finally a reader will find a description of variable two-dimensional methods applied in the analysis of compounds, most commonly encountered in plant extracts. This paper is aimed to draw attention to the potential of two-dimensional planar chromatography in the field of phytochemistry. It may be useful for those who are interested in achieving successful separations of multicomponent mixtures by means of two-dimensional TLC.
近年来，源自药用植物的药物正经历复兴。这归因于草药具有巨大的药理潜力，因为已发现许多天然化合物具有广谱生物活性。引入整株植物、植物提取物或分离出的天然化合物导致需要创建适用于其分析的方法。鉴定分离出的物质相对容易，但分析植物提取物会引发诸多问题，因为它们通常是非常复杂的混合物。色谱方法是分析天然混合物中最常用的技术之一。不幸的是，传统的一维技术的分离能力通常不足以分离更复杂的样品。在这种情况下，建议使用多维色谱法。平面色谱法提供了使用一种吸附剂和两种不同洗脱剂进行二维分离的可能性，或者通过使用双层板或接枝薄层色谱（TLC）技术；不同多维技术的组合也是可能的。本文综述了常用于分析天然化合物的多维平面色谱方法。详细介绍了在一种吸附剂上、双层板上、使用接枝TLC和联用方法进行二维分离的方法。还描述了液相色谱中多维性的一般方面。最后，读者将看到对用于分析植物提取物中最常见化合物的可变二维方法的描述。本文旨在引起人们对二维平面色谱在植物化学领域潜力的关注。对于那些有兴趣通过二维TLC成功分离多组分混合物的人可能会有所帮助。
