Cuyckens Filip, Shahat Abdelaaty A, Pieters Luc, Claeys Magda
Department of Pharmaceutical Sciences, University of Antwerp (UIA), Universiteitsplein 1, B-2610 Antwerp, Belgium.
J Mass Spectrom. 2002 Dec;37(12):1272-9. doi: 10.1002/jms.402.
Mass spectrometric methods have been developed which allow the direct stereochemical assignment of terminal monosaccharide residues in flavonoid O-glycosides without the need for chemical hydrolysis. Standards containing a glucose, galactose, mannose, xylose, arabinose or apiose residue were examined because these monosaccharides are by far the most commonly encountered in flavonoid glycosides. Following acetylation, the major peracetylated sugar related fragments, generated by fast atom bombardment (FAB) or electrospray ionization (ESI), were selected for collisional activation employing a broad range of collision energies. Both FAB and ESI proved to be useful as ionization techniques. Stereoselective fragmentation was achieved and allowed us clearly to differentiate and characterize isomeric monosaccharide residues. The method developed was successfully applied to an unknown flavonoid containing a terminal pentose and hexose residue which was isolated from Farsetia aegyptia.
已经开发出质谱方法，无需化学水解就能直接对黄酮类O-糖苷中的末端单糖残基进行立体化学归属。对含有葡萄糖、半乳糖、甘露糖、木糖、阿拉伯糖或芹糖残基的标准品进行了检测，因为这些单糖是黄酮类糖苷中最常见的。乙酰化后，通过快原子轰击（FAB）或电喷雾电离（ESI）产生的主要全乙酰化糖相关碎片，使用广泛的碰撞能量进行碰撞活化。结果表明，FAB和ESI都是有用的电离技术。实现了立体选择性裂解，使我们能够清楚地区分和表征异构单糖残基。所开发的方法成功应用于从埃及紫堇中分离出的一种含有末端戊糖和己糖残基的未知黄酮类化合物。
