Reversed-phase HPLC-ESI/MS analysis of birch leaf proanthocyanidins after their acidic degradation in the presence of nucleophiles
Reversed-phase HPLC-ESI/MS analysis of birch leaf proanthocyanidins after their acidic degradation in the presence of nucleophiles
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DOI：
10.1002/pca.992
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发表时间：
2007-09-01
影响因子：
3.3
通讯作者：
Pihlaja, Kalevi
中科院分区：
文献类型：
--
作者：
Karonen, Maarit;Leikas, Anne;Pihlaja, Kalevi
山桦树叶中含有大量结构可变的多聚原花青素。通过在Sephadex LH-20柱层析前加入液-液萃取物，加强了它们的分离过程。在苯硫醇或间苯三酚存在下酸催化解聚分离的多聚原花青素，以研究其组成。降解产物黄烷-3-醇和黄烷-3-醇加合物用反相高效液相色谱-紫外光电二极管阵列检测定量，电喷雾电离质谱仪鉴定。结果表明，聚合物原花青素以(Epi)没食子儿茶素和(Epi)儿茶素为延伸单元，主要以(+)-儿茶素为末端单元。基于硫解的平均聚合度为26，基于间苯三酚降解的平均聚合度为31。版权所有(C)2007 John Wiley&Sons，Ltd.
Mountain birch leaves contain large amounts of structurally variable polymeric proanthocyanidins. Their isolation procedure was enhanced by the addition of liquid-liquid extractions prior to column chromatography over Sephadex LH-20. Isolated polymeric proanthocyanidins were depolymerised by acid-catalysis in the presence of benzyl mercaptan or phloroglucinol in order to study their composition. The resulting degradation products, flavan-3-ols and flavan-3-ol adducts, were analysed with reversed-phase high-performance liquid chromatography using UV photodiode array detection for quantification and electrospray ionisation mass spectrometry for identification. The results showed that polymeric proanthocyanidins contained (epi)gallocatechins and (epi)catechins as the extension units and, mainly, (+)-catechin as the terminal unit. The mean degree of polymerisation was found to be 26 based on thiolysis and 31 based on phloroglucinol degradation. Copyright (c) 2007 John Wiley & Sons, Ltd.