槲皮素的电喷雾离子阱质谱分析

应用电喷雾离子阱正负离子扫描技术对槲皮素的结构和质谱裂解规律进行比较研究，并采用Mass Frontier 3.0软件辅助解析正离子扫描条件下槲皮素的主要特征碎片离子及其裂解规律。槲皮素正离子扫描的ESI MS裂解特征是出现碎片 m/z 287、285、275、267、257及229，碎片m/z 285和275可继续裂解成碎片 m/z 257、229。碎片 m/z 283、273、257、245和229的形成及碎片 m/z 283、273裂解成碎片 m/z 255是槲皮素负离子扫描的ESI-MS裂解特征。槲皮素的正负离子扫描质谱裂解规律基本相似，但负离子提供的碎片信息较少。本研究为进一步探求该化合物的体内代谢转化，结构优化和修饰提供了有价值的依据。

Elucidation of Quercetin by Electron Spray Ionization Mass Spectrometry

Positive and negative electron spray ionization mass spectrometry (ESI-MS) was used to analyse the chemical structure and MS/MS fragmentation pathway of quercetin.The positive ESI-MS characteristic ions and fragmentation mechanism of quercetin were elucidated and explained by the program of Mass Frontier 3.0. Fragment ions m/z 287, 285,275, 267, 257 and 229 are existed at the positive ion mode, and the fragment m/z 285 and 275 are further fragmented to form m/z 257 and 229. These ions are the fragmentation characteristics of quercetin in the positive ESI-MS. Fragment ions m/z 283, 273, 257, 245,229 are the fragmentation characteristics in negative ESI-MS, and the fragment m/z 255 is formed by m/z 283 or m/z 273. The fragmentation pathway in positive and negative ESI-MS is similar, but the negative ESI-MS mode provides less fragment ions. These results provide the very important information for the drug metabolic research and the structural modification of quercetin.