Tzouros Manuel, Manov Nikolay, Bienz Stefan, Bigler Laurent
Institute of Organic Chemistry, University of Zurich, Zurich, Switzerland.
J Am Soc Mass Spectrom. 2004 Nov;15(11):1636-43. doi: 10.1016/j.jasms.2004.07.020.
The fragmentation mechanism of the acylpentamine toxins 1-4 found in the venom of the spider Agelenopsis aperta has been investigated in detail. To identify the origin of the two doublets of unexpected fragment ions at m/z 129/112 and m/z 115/98, three synthetic 15N-labeled analogs 5-7 have been prepared and subjected to CID fragmentation on a triple quadrupole mass spectrometer. It appears that the unexpected doublet of fragment ions arises from an internal portion of the polyamine backbone after either a transaminative Zip reaction or a sequential fragmentation of the quasi-molecular ion. The second option has been proven by in-source CID experiments. The detailed knowledge of acylpentamine fragmentation mechanisms is essential for the correct characterization of isomeric compounds, particularly for coeluting compounds within complex mixtures such as spider venoms.
已对在黑腹漏斗蛛毒液中发现的酰基五胺毒素1 - 4的裂解机制进行了详细研究。为了确定在m/z 129/112和m/z 115/98处意外碎片离子的两个双峰的来源，制备了三种合成的15N标记类似物5 - 7，并在三重四极杆质谱仪上进行碰撞诱导解离（CID）裂解。看来，意外的碎片离子双峰是在转氨Zip反应或准分子离子的连续裂解后，由多胺主链的内部部分产生的。通过源内CID实验证明了第二种情况。酰基五胺裂解机制的详细知识对于异构体化合物的正确表征至关重要，特别是对于复杂混合物（如蜘蛛毒液）中同时洗脱的化合物。
