National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado, USA.
J Am Soc Mass Spectrom. 1996 Feb;7(2):129-39. doi: 10.1016/1044-0305(95)00629-X.
The low energy collision induced dissociation (CID) of the carboxylate anions generated by electrospray ionization of leukotriene B4 (LTB4) and 16 of its metabolites was studied in a tandem quadrupole mass spectrometer. LTB4 is a biologically active lipid mediator whose activity is terminated by metabolism into a wide variety of structural variants. The collision-induced dissociation spectra of the carboxylate anions revealed structurally informative ions whose formation was determined by the position of hydroxyl substituents and double bonds present in the LTB4 metabolite. Major ions resulted from charge remote α-hydroxy fragmentation or charge directed α-hydroxy fragmentation. The conjugated triene moiety present in some metabolites was proposed to undergo cyclization to a 1,3-cyclohexadiene structure prior to charge remote or charge driven a-hydroxy fragmentation. The mechanisms responsible for all major ions observed in the CID spectra were studied using stable isotope labeled analogs of the LTB4 metabolites. In general, the collision-induced decomposition of carboxylate anions produced unique spectra for all LTB4 derived metabolites. The observed decomposition product ions from the carboxylate anion could be useful in developing assays for these molecules in biological fluids.
采用串联四极杆质谱仪研究了电喷雾电离生成的白三烯 B4（LTB4）及其 16 种代谢产物的羧酸根阴离子的低能量碰撞诱导解离（CID）。LTB4 是一种生物活性脂质介质，其活性通过代谢转化为多种结构变体而终止。羧酸根阴离子的碰撞诱导解离谱揭示了结构信息丰富的离子，其形成取决于 LTB4 代谢产物中羟基取代基和双键的位置。主要离子是由远程电荷诱导 α-羟基断裂或电荷导向 α-羟基断裂形成的。一些代谢产物中存在的共轭三烯部分被提议在远程电荷或电荷驱动的 a-羟基断裂之前环化成 1,3-环己二烯结构。使用 LTB4 代谢物的稳定同位素标记类似物研究了 CID 谱中观察到的所有主要离子的反应机制。一般来说，羧酸根阴离子的碰撞诱导分解为所有 LTB4 衍生的代谢产物产生了独特的谱图。从羧酸根阴离子中观察到的分解产物离子可能有助于在生物流体中开发这些分子的测定方法。
