Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing 100048, China.
Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing 100048, China.
J Chromatogr A. 2021 Jan 11;1636:461772. doi: 10.1016/j.chroma.2020.461772. Epub 2020 Dec 2.
Ferulic acid stereoisomers are the most abundant phenolic acids in cereal bran. However, it is challenging to separate them because of the similar structures and properties. In this study, a preparative separation method of ferulic acid stereoisomers from the crude extract of wheat bran was successfully developed. The method contained a two-step separation, the traditional counter-current chromatography (CCC, hexane: ethyl acetate: methanol: water = 2:5:2:4) was followed with a pH-zone-refining CCC (hexane: ethyl acetate: acetonitrile: water = 2:5:2:2, 10 mmol L trifluoroacetic acid in organic stationary phase and 10 mmol L ammonia in aqueous mobile phase). Trans-ferulic acid and cis-ferulic acid with HPLC high purity over than 99% and 98% can be yielded in large-scale separation. Moreover, it is found that different proton affinity, deprotonation ability and interaction site of hydrogen bond result in distinct partition behavior of stereoisomers, which is illustrated by quantitative analysis of molecular surface. This contributes to our in-depth understanding of the separation mechanism toward pH-zone refining CCC. The developed method can be applied in the exploitation of ferulic acids and related phenolic acids from other resources.
阿魏酸对映异构体是谷物麸皮中含量最丰富的酚酸。然而，由于其结构和性质相似，因此很难将其分离。在这项研究中，成功开发了一种从麦麸粗提取物中分离阿魏酸对映异构体的制备分离方法。该方法包含两步分离，首先是传统逆流色谱（CCC，正己烷：乙酸乙酯：甲醇：水= 2：5：2：4），然后是 pH 区带精制 CCC（正己烷：乙酸乙酯：乙腈：水= 2：5：2：2，有机固定相中的 10 mmol L 三氟乙酸和水相中的 10 mmol L 氨）。通过大规模分离，可以得到 HPLC 纯度高于 99%和 98%的反式阿魏酸和顺式阿魏酸。此外，研究还发现不同的质子亲和力、去质子化能力和氢键相互作用位点导致对映异构体的分配行为明显不同，这通过分子表面的定量分析得到了说明。这有助于我们深入了解 pH 区带精制 CCC 的分离机制。所开发的方法可应用于从其他资源中提取阿魏酸和相关酚酸。
