Resolvin D1, protectin D1, and related docosahexaenoic acid-derived products: Analysis via electrospray/low energy tandem mass spectrometry based on spectra and fragmentation mechanisms
Resolvin D1, protectin D1, and related docosahexaenoic acid-derived products: Analysis via electrospray/low energy tandem mass spectrometry based on spectra and fragmentation mechanisms
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DOI：
10.1016/j.jasms.2006.09.002
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发表时间：
2007-01-01
影响因子：
3.2
通讯作者：
Serhan, Charles N.
中科院分区：
文献类型：
--
作者：
Hong, Song;Lu, Yan;Serhan, Charles N.
解决素D_1(RvD_1)和保护素D_1(神经保护素D_1，PD1/NPD1)是由二十二碳六烯酸(DHA)生物合成的新发现的抗炎脂质介质。本文利用电喷雾低能碰撞诱导解离串联质谱仪(MS/MS)研究了生物来源的RvD1和PD1以及单羟基DHA和相关的羟基DHA的光谱-结构关联和裂解机理。光谱中H2O和CO2的损失表明官能团的数量(S)。断链离子是官能团和双键的位置和数目的标志。观察到的断链离子相当于一个假设的均解段(cc、cm、mc或mM)，添加或提取最多2个质子(H)。A-裂解离子相当于：[CC+H]，H通过β-烯或伽马-烯重排来自羟基；[Cm-2H]，通过伽马-烯重排来自PD1的羟基，或1H来自羟基，另一个H来自单-HDHA的α-碳，通过α-H-β-烯重排；[MC-H]，H来自羟基，通过β-烯或y-烯重排，或来自α-碳通过α-H-β-烯重排；或[mm]，通过电荷直接碎裂。β-烯或y-烯促进了H向y位的转移和a-裂解。氚标记证实了MS/MS离子的归属和裂解机理。根据MS/MS谱图和裂解机制，我们在人中性粒细胞和血液、鲑鱼头肾和中风损伤小鼠脑组织中鉴定了RvD1、PD1和单羟基-DHA产物。
Resolvin D1 (RVD1) and protectin D1 (Neuroprotectin D1, PD1/NPD1) are newly identified anti-inflammatory lipid mediators biosynthesized from docosahexaenoic acid (DHA). In this report, the spectra-structure correlations and fragmentation mechanisms were studied using electrospray low-energy collision-induced dissociation tandem mass spectrometry (MS/MS) for biogenic RvDl and PD1, as well as mono-hydroxy-DHA and related hydroperoxy-DHA. The loss of H2O and CO2 in the spectra indicates the number of functional group(s). Chain-cut ions are the signature of the positions and numbers of functional groups and double bonds. The observed chain-cut ion is equivalent to a hypothetical homolytic-segment (cc, cm, mc, or mm) with addition or extraction of up to 2 protons (H). The a-cleavage ions are equivalent to: [cc + H], with H from the hydroxyl through a beta-ene or gamma-ene rearrangement; [cm - 2H], with 2H from hydroxyls of PD1 through a gamma-ene rearrangement, or 1H from the hydroxyl and the other H from the alpha-carbon of mono-HDHA through an alpha-H-beta-ene rearrangement; [mc - H], with H from hydroxyl through a beta-ene or y-ene rearrangement, or from the alpha-carbon through an alpha-H-beta-ene rearrangement; or [mm] through charge-direct fragmentations. The beta-ene or y-ene facilitates the H shift to y position and a-cleavage. Deuterium labeling confirmed the assignment of MS/MS ions and the fragmentation mechanisms. Based on the MS/MS spectra and fragmentation mechanisms, we identified RVD1, PD1, and mono-hydroxy-DHA products in human neutrophils and blood, trout head-kidney, and stroke-injury murine brain-tissue.