Laboratório de Quimiometria em Ciências Naturais, Departamento de Química, Universidade Estadual de Londrina, Caixa Postal 6001, CEP 86051-970, Londrina, Paraná, Brazil.
Anal Chim Acta. 2011 Sep 30;702(2):288-94. doi: 10.1016/j.aca.2011.06.056. Epub 2011 Jul 8.
The effects of four solvents, hexane, dichloromethane, ethyl acetate, methanol, and their mixtures on the separation of metabolites in crude extracts of Erythrina speciosa Andrews leaves were investigated using two strategies for open column chromatography. The classical extraction procedure was compared with mobile phases prepared according to a mixture design in order to explore the effects of solvent interactions on metabolite separations. Principal component analysis was used to compare the UV spectra obtained from RP-HPLC-DAD and to estimate the number of independent factors contained in the chromatographic data of the extracts. The results showed that, in addition to solvent polarity, solvent mixtures play an important role in metabolite separation. When pure solvents are used, larger groups of similar spectra are observed in the factor analysis score graphs indicating the same or a limited number of metabolite classes. In contrast solvent mixtures produced score graphs with a larger number of clusters indicating greater metabolic diversity. Besides resulting in more peaks than the pure solvents the chromatographic data of the design mixtures resulted in larger numbers of significant principal components confirming the greater chemical diversity of their extracts. Thus, if the objective of an analysis is to obtain metabolites of the same class, one should use pure solvents. On the other hand, binary and ternary solvent mixtures are recommended for more efficient investigations of class diversity and richer metabolite fingerprints.
采用两种开柱色谱策略研究了四种溶剂（正己烷、二氯甲烷、乙酸乙酯和甲醇）及其混合物对鸡骨草（Erythrina speciosa Andrews）叶粗提物中代谢物分离的影响。将经典提取程序与根据混合设计制备的流动相进行了比较，以探究溶剂相互作用对代谢物分离的影响。采用主成分分析法比较了从 RP-HPLC-DAD 获得的 UV 光谱，并估算了提取物色谱数据中包含的独立因子的数量。结果表明，除溶剂极性外，溶剂混合物在代谢物分离中也起着重要作用。当使用纯溶剂时，因子分析得分图中观察到更多具有相似光谱的较大组群，表明具有相同或有限数量的代谢物类别。相比之下，溶剂混合物产生的得分图具有更多的聚类，表明具有更大的代谢多样性。设计混合物的色谱数据不仅比纯溶剂产生更多的峰，而且还产生更多的显著主成分，证实了其提取物具有更大的化学多样性。因此，如果分析的目的是获得相同类别的代谢物，则应使用纯溶剂。另一方面，二元和三元溶剂混合物则推荐用于更有效地研究类别多样性和更丰富的代谢物指纹图谱。
