超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法探究大环内酯类质谱裂解规律

Study on the fragmentation pathway of macrolide antibiotics by ultra-performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry

目的采用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法研究大环内酯类化合物的质谱裂解规律。方法采用Waters ACQUITY UPLC BEH Shield RP 18(2.1 mm×50 mm,1.7μm)色谱柱,以甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱,在电喷雾正离子模式下采集数据,采用全扫描和数据依赖的二级扫描模式,根据一、二级质谱离子的精确质荷比推导大环内酯类化合物可能的裂解途径。11种大环内酯类抗生素主要发生糖苷键的断裂。结果替米考星、吉他霉素、交沙霉素、泰乐菌素和螺旋霉素主要的特征离子碎片为m/z 174.11247、m/z 156.10191以及m/z 116.07060,同时丢失中性分子H2O。琥乙酰红霉素酯、竹桃霉素、泰利霉素、地红霉素、依托红霉素和克拉霉素主要的特征离子碎片为m/z 158.11756、m/z 116.10699以及m/z 98.09643,同时丢失中性分子H2O。结论该研究提出的质谱裂解规律为快速鉴定和分析复杂基质中相似结构特征的大环内酯类化合物提供重要依据。

Objective To study the fragmentation pathways of macrolide antibiotics by ultra-performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry.Methods The compounds were separated by Waters ACQUITY UPLC BEH Shield RP 18(2.1 mm×50 mm,1.7μm)with methanol and 0.1%formic acid aqueous solution as mobile phase for gradient elution.The data were collected by positive electrospray ion mode.The possible cleavage pathways of macrolides were deduced according to the precise mass/charge ratio of the first and second order mass spectra by using full scanning and data dependent second order scanning mode.Glycosidic bond fracture was the main cause of 11 macrolides antibiotics.Results The major fragments ions of tilmicosin,leucomycin,josamycin,tylosin and spiramycin were m/z 174.11247、m/z 156.10191 and m/z 116.07060,coupled with neutral loss of H2O.The major fragments ions of erythromycin ethylsuccinate,oleandomycin,telithromycin,dirithromycin,erythromycin estolate and clarithromycin were m/z 158.11756、m/z 116.10699 and m/z 98.09643,coupled with neutral loss of H2O.Conclusion The mass spectrometric decomposition rule proposed in this study provides an important basis for the rapid identification and analysis of macrolides with similar structural characteristics in complex matrix.