Sesquiterpene lactones (SL) have been reported with various biological effects. Among the described SL skeletons, hirsutinolide and glaucolide have not been extensively studied by mass spectrometry (MS), especially how to distinguish them in organic matrices. Thus, this paper reports (1) a strategy of their differentiation based on MS behavior during the ionization and (2) a proposal of the fragmentation pattern for both SL-subtypes. ESI(+)-HRMS data of four isolated SL (hirsutinolides 1 and 3; glaucolides 2 and 4) were recorded by direct and UPLC water-sample combined injections. These analyses revealed that hirsutinolides and glaucolides formed [M+Na]+ ion during the operation of the direct MS injection, and ([M+Na]+ and [M+H-H2 O]+ ) and [M+H]+ ions were respectively observed for hirsutinolides and glaucolides during the operation of combined UPLC water and sample MS injection. Computational simulations showed that the complex hirsutinolide (1)-Na+ formed with a lower preparation energy compared with the complex glaucolide (2)-Na+ . However, despite their different behavior during the ionization process, ESI(+)-HRMS/MS analyses of 1-4 gave similar fragmentation patterns at m/z 277, 259, 241, and 231 that can be used as diagnostic ions for both skeletons. Moreover, the differentiation strategy based on the nature of the complex SL-adducts and their MS/MS fragmentation pattern were successfully applied for the chemical characterization of the extract from Vernonanthura tweedieana using UPLC-ESI-HRMS/MS. Among the characterized metabolites, SL with hirsutinolide and glaucolide skeletons showed the aforementioned diagnostic fragments and an ionization behavior that was similar to those observed during the water-sample combined injection.

中文翻译：

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Es-QTof-MS表征hirsutinolide和glaucolide倍半萜内酯：基于复杂混合物中Na + / H +加合物相互作用的裂解机理和分化。

据报道倍半萜内酯（SL）具有多种生物学作用。在所描述的SL骨架中，hirsutinolide和glaucolide尚未通过质谱（MS）进行广泛研究，尤其是如何在有机基质中区分它们。因此，本文报道了（1）基于电离过程中MS行为的区分策略，以及（2）提出了两种SL亚型的片段化模式的建议。通过直接和UPLC水样联合进样记录了四个分离的SL（水ut素内酯1和3；青草酸酯2和4）的ESI（+）-HRMS数据。这些分析表明，在直接MS注射操作期间，hirsutinolides和glaucolides形成了[M + Na] +离子，在UPLC水和样品MS的组合进样操作中，分别观察到了hirsutinolides和glaucolides的离子和[[M + Na] +和[M + H-H2 O] +]和[M + H] +离子。计算模拟表明，与复杂的青草酸酯（2）-Na +相比，形成的hirsutinolide（1）-Na +复合物的制备能更低。但是，尽管它们在电离过程中的行为不同，但1-4的ESI（+）-HRMS / MS分析在m / z 277、259、241和231处给出了相似的碎片模式，可用作两个骨架的诊断离子。此外，基于复杂的SL加合物的性质及其MS / MS片段化模式的分化策略已成功应用于UPLC-ESI-HRMS / MS对Vernonanthura tweedieana提取物的化学表征。在代谢产物中，