摘要
利用离子阱飞行时间质谱仪的高质量精度、高分辨率及多级测定性能,对儿茶素类化合物(二组对映异构体)质谱裂解进行研究,并利用氢/氘交换法对裂解方式进行确证.发现儿茶素对映异构体间具有相同的质谱裂解途径,多级质谱无明显区别.在二级质谱中,表儿茶素/儿茶素(EC/C)丢失的CO2发生在A环,丢失的C2H2O发生在B环.1,4A-,1,3A-,1,2A-和[M-H-B环]-4个碎片离子为EC/C特征离子,通过这4个离子质量数变化,推测A环上的取代情况.因表儿茶素没食子酸酯/儿茶素没食子酸酯(ECG/CG)结构上都含有没食子酸取代基,在二级质谱中均可见m/z169特征峰,此离子可用于ECG/CG和EC/C区分.
The fragmentation pathways of tea catechins （two group stereoisomers ） were studied via the iontrap time-of-flight （IT-TOF） mass spectrometer with the advantages of high mass accuracy, high resolution, multistage analysis. Hydrogen/deuterium exchange method was used to elucidate the fragmentation processes. The results show that eatechin stereoisomers possess the same fragmentation pathways and cannot be differentiated even in MSn spectra. We can locate the loss of CO2 and C2H2O in MS2 spectra from EC/C to A ring and B ring, respectively. The ions of ^1,4A-, ^1,3A-, ^1,2A- and [ M -H -B ring] - were characteristic product ions for EC/C, and it could be used to propose the substituent group of A ring through the m/z shift of these ions. The ion at m/z 169 corresponding to the gallic acid anion was characteristic fragmentation of ECG/CG, which was great helpful for differentiating ECG/CG and EC/C.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2009年第8期1566-1570,共5页
Chemical Journal of Chinese Universities
基金
国家"九七三"计划(批准号:2006CB504707)资助
作者简介
端裕树，男，博士，研究员，主要从事仪器分析方面的研究．E-mail：y-hashi@shimadzu．co.jp
陈世忠，男，博士，副教授，主要从事天然药物化学研究．E-mail：chenshizhong66@163．com
