Characterizations of the hydrolyzed products of ginkgolide A and ginkgolide B by liquid chromatography coupled with mass spectrometry.
Characterizations of the hydrolyzed products of ginkgolide A and ginkgolide B by liquid chromatography coupled with mass spectrometry.
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DOI：
10.1016/j.jpba.2015.10.029
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发表时间：
2016-01
影响因子：
3.4
通讯作者：
Ke Lan;Xuejing Li;Gang Du;Liang Xu
中科院分区：
文献类型：
--
作者：
Ke Lan;Xuejing Li;Gang Du;Liang Xu
银杏内酯是二萜三内酯，负责银杏叶提取物的神经调节特性。它们在水溶液中水解为混合羧酸盐形式，可能包括三种单羧酸盐、三种二羧酸盐和一种三羧酸盐。水解产物的表征具有挑战性，因为无法单独制备它们。在这项工作中，银杏内酯 A (GA) 和银杏内酯 B (GB) 的主要水解产物（包括所有三种单羧酸盐）在缓冲液中产生，并进行液相色谱、三重四极杆 MS 和 LTQ Orbitrap MS 分析。通过对GA和GB的三内酯的比较分析，强调了内酯-C上CO两次中性损失的独特的电荷驱动裂解途径。因此，根据与三内酯交联的断裂途径的构建，对单羧酸酯进行了鉴定。简而言之，内酯-C 水解产物的特点是 [M − H]− 和 [M − H − C2H2O3]−（GA 为 m/z351，GB 为 m/z367）之间不存在产物离子。内酯-F 水解产物的特征裂解途径是环 A 的裂解，产生片段（对于 GA 为 m/z295，对于 GB 为 m/z309），然后两次 (GA) 或三次 (GB) 中性损失 CO。内酯-E 水解产物的最具特征性的片段是 [M − H − H2O − CO2− 2CO]−(m/z307 对于 GA和 m/z323（GB））与其他两种单羧酸盐形成对比。这项工作中获得的知识对于研究银杏内酯的生物学命运和相应的药理机制具有特殊用途。
Ginkgolides are diterpenoid trilactones responsible for the neuromodulatory properties ofGinkgo bilobaextracts. They are to be hydrolyzed in aqueous solutions as mixed carboxylate forms potentially including three monocarboxylates, three dicarboxylates and one tricarboxylate. Characterizations of the hydrolyzed products are challenging because there is no way to prepare them individually. In this work, the major hydrolyzed products of ginkgolide A (GA) and ginkgolide B (GB) including all three monocarboxyaltes have been produced in buffers and subjected to liquid chromatography coupled with triple quadrupole MS and LTQ Orbitrap MS analysis. With the comparative analysis of the trilactone of GA and GB, it was highlighted a unique charge-driven fragmentation pathway of twice neutral losses of CO on the lactone-C. The monocarboxylates were accordingly identified based on the construction of their fragmentation pathways cross-linked with those of the trilactone. In brief, the lactone-C hydrolyzed product is characteristic of the absence of product ions between [M − H]−and [M − H − C2H2O3]−(m/z351 for GA andm/z367 for GB). The featured fragmentation pathway of the lactone-F hydrolyzed product is the cleavage of ring-A, yielding a fragment (m/z295 for GA andm/z309 for GB) followed with twice (GA) or triple (GB) neutral losses of CO. The most characteristic fragment of the lactone-E hydrolyzed product is [M − H − H2O − CO2− 2CO]−(m/z307 for GA andm/z323 for GB) in contrast to the other two monocarboxylates. The knowledge gained in this work was of special uses to investigate the biological fates and the corresponding pharmacological mechanisms of ginkgolides.