Preferential alkali metal adduct formation by <i>cis</i>
geometrical isomers of dicaffeoylquinic acids allows for efficient discrimination from their <i>trans</i>
isomers during ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry
作者:Mpho M. Makola、Paul. A Steenkamp、Ian A. Dubery、Mwadham M. Kabanda、Ntakadzeni E. Madala
DOI:10.1002/rcm.7526
日期:2016.4.30
RATIONALE Caffeoylquinic acid (CQA) derivatives are a group of structurally diverse phytochemicals that have attracted attention due to their many health benefits. The structural diversity of these molecules is due in part to the presence of regio- and geometrical isomerism. This structural diversity hampers the accurate annotation of these molecules in plant extracts. Mass spectrometry (MS) is successfully
理性咖啡酰奎尼酸(CQA)衍生物是一组结构多样的植物化学物质,由于它们具有许多健康益处,因此引起了人们的关注。这些分子的结构多样性部分归因于区域和几何异构现象的存在。这种结构多样性妨碍了植物提取物中这些分子的准确注释。质谱(MS)已成功用于区分CQA衍生物的不同区域异构体;然而,事实证明,对这些分子的几何异构体进行准确区分是一项艰巨的任务。方法采用超高效液相色谱/四极杆飞行时间质谱(UHPLC / QTOFMS)方法在负离子化模式下对diCQA的甲醇溶液进行紫外线辐射分析。通过改变毛细管电压和锥孔电压来优化源内碰撞诱导解离(ISCID)方法,以实现MS分析过程中diCQA的UV生成的几何异构体之间的差异碎片化模式。结果毛细管电压的变化并没有引起四种几何异构体的断裂图谱的显着差异,而视锥电压的变化却导致了断裂图谱的显着差异。结果还首次显示,与diCQAs的反式对应物相比,diCQAs的顺式几