Document Type

Journal Article

Department/Unit

School of Chinese Medicine

Language

English

Abstract

The fragmentation behavior of isoflavones was studied using electrospray ionization-ion trap-time of flight mass spectrometry (ESI-IT-TOF-MSn). It was found that the isoflavone glycoside bond was easily broken. The fragmentation occurred mostly on the C-ring, and the fragment ions of A1,3+ produced bythe RDA cracking will predict the hydroxylation replacement on A-ring or B-ring. In addition, four carbonyl groups on the C-ring were fragmented through neutral loss of 28 (-CO). A and B-rings primarily lose substituents which including a neutral losses of 32 (-CH3OH), 16 (-CH4), or 16 (-O), and 18 (-H2O). A-ring in the presence of adjacent hydroxylation, also easily made to be a neutral losses of 28 (-CO) or 18 (-H2O). It is likewise common to see methoxy replaced with a neutral losses of 16 (-CH4) or 32 (-CH3OH) in B-ring, also the hydroxylation on benzene ring can occasionally results with the neutral loss of 28 (-CO).

本文对选定的11个异黄酮化合物在ESIITTOFMS n 的裂解规律进行研究。文章采用ESIITTOFMS n 仪对样品 进行高分辨质谱测定, 正负离子多级切换, 通过对质谱碎片离子进行预测, 并根据结构对其质谱可能的裂解规律进行总结 研究。由于在正离子模式下信号较强, 采用正离子模式对11个异黄酮多级碎片离子分析, 发现异黄酮苷的裂解主是优先 断裂糖苷键; C环4位羰基易于中性丢失CO (–28), 而C环经过RDA裂解形成的A 1,3+ 则能够比较A环与B环上的羟基取代位置; A环上有相邻羟基存在时, 也易中性丢失CO (–28)或H2O (–18); B环有甲氧基取代时中性丢失CH4 (–16)、自由基 (CH3)或 CH3OH (–32)为常见, 但A环与B环有单独羟基时也偶见中性丢失CO (–28)。通过ESIITTOFMS n 方法, 选定多级正离子模式 下对异黄酮的裂解进行了总结, 有利于了解异黄酮在质谱中的裂解行为, 对于异黄酮类化合物相关的结构推测有重要意义。

Keywords

Isoflavone, Fragmentation behavior, ESI-IT-TOF-MSn, 异黄酮, 裂解规律, 高分辨多级质谱技术

Publication Date

9-2014

Source Publication Title

Journal of Chinese Pharmaceutical Sciences = 中国药学(英文版)

Volume

23

Issue

9

Start Page

631

End Page

641

Publisher

Beijing Medical University

Peer Reviewed

1

Copyright

© 2014 Journal of Chinese Pharmaceutical Sciences, School of Pharmaceutical Sciences, Peking University

Funder

This study was financially supported by Hong Kong Baptist University Faculty Research Foundation (Grant No. FRG2/12-13/058), and by the Key Program of Guangxi Natural Science Foundation of China (Grant No. 2013GXNSFBA019187).

DOI

10.5246/jcps.2014.09.081

Link to Publisher's Edition

http://dx.doi.org/10.5246/jcps.2014.09.081

ISSN (print)

10031057

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