类肝素化合物的傅立叶变换离子回旋共振-电喷雾质谱研究

Characterization of Synthetic Heparin-like Compounds by Negative Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

采用负离子模式的电喷雾傅立叶变换离子回旋共振质谱(ESI-FTICR-MS)对3个合成的肝素类化合物DHα、THα和THβ进行了全扫描一级谱和持续非共振辐照碰撞诱导解离(SORI-CID)串联质谱分析。样品浓度10μmol/L,流动泵注射直接进样。化合物中的磺酸胺和磺酸酯结构容易在一般电喷雾条件下发生分解,失去一个或者多个SO3,一级全扫描谱图中得到的谱峰均是带有单电荷或者双电荷的准分子离子峰。在串联质谱中,部分双电荷离子发生解离时,其二级谱图中子离子由单电荷子离子和双电荷子离子共同组成。通过对谱峰的局部放大,利用同位素峰的峰间距,能直接给出子离子的带电荷情况。同时,结合FTICRMS提供的高质量精度质谱数据,能够对所选取母离子的碎裂途径进行确认。离子质荷比测量的平均误差小于3.0×10-6。为结构复杂的类肝素化合物的质谱分析提供了借鉴。

The full scan and sustained off-resonance irradiation collision induced dissociation（SORI-CID） techniques were employed to study three synthetic heparin-like compounds DHα,THα and THβ in negative mode using electrospray ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry（ESI FTICR-MS）.The concentration of stock solution was 10 μmol/L.The stock solutions were introduced into the FT-ICR-MS by syringe pump directly.The structure of sulfamin and sulfonate inside the heparin-like compounds can undergo one or more neutral losses of SO3 under the soft electrospray ionization condition.The single and double charged pseudomolecular ions presented in the full scan spectra of these compounds.Some double charged pseudomolecular ions produced single or double charged fragments,which were deduced from the isotope profile of product ions.The fragmentation pathways of selected precursor ions were assigned by combining the ultrahigh measurement accuracy of their FTICR MS data and fragments＇ charge.The mean errors of the measured mass to charge ratios were less than 3.0×10^-6.The results provide references for the analysis of complex heparin-like compounds by mass spectrometry.