舒它西林的电喷雾-四极杆-飞行时间串联质谱裂解规律研究

Study on the Cleavage Rule of Sultamicillin by Electrospray Ionization-Quadrupole Time-of-Flight Mass Spectrometry

为阐明药物舒它西林(氨苄西林/舒巴坦)的质谱裂解规律,采用电喷雾-四极杆-飞行时间串联质谱(ESI-Q-TOF-MS/MS)法在正离子模式下,对其离子碎片结构进行分析。通过质谱的高分辨能力及同位素氘代信息推断出舒它西林[M+H]+碎片离子断裂途径主要为氨苄西林部分的β-内酰胺环断裂,[M+Na]+裂解可观察到较多碎片离子峰,包括氨苄西林部分β-内酰胺环断裂、双酯连接处断裂和舒巴坦部分四元环断裂,此外有脱去CO2、SO2、CO等中性分子的峰出现。两种分析模式可为舒它西林的结构解析、体内代谢物质或环境中降解产物的研究提供快速鉴别理论依据。

In order to clarify the fragmentation behaviors of Sultamicillin （ampicillin/sulbactam）, Sultamicillin was investigated by the electrospray ionization - quadrupole - time of flight tandem （ESI-Q-TOF-MS/MS） mass spectrometry in positive ion mode. The fragmentation pathways were elucidated based on the high-resolution of mass spectrometer and iso- tope-labelling experiment. It was found that the protonated precursor ion [M＋ HI＋ mainly fractured through β-lactam ring of Ampicillin. The [M＋Na]＋ precursor ion provided more product ions fragmentation by the cleavage of β-lactam, diesters and four-member ring of Sulbactam part. In addition, the loss of neutral molecules such as CO2, SO2, CO was oc- curred readily. The fragmentation experiment of [M＋ H]＋ and [M＋Na-]＋ precursor ions could provide theoretical knowledge for the rapid identification of structural analysis, metabolites in vivo and degradation products in the environment of Sultamicillin.