ESI‐QTof‐MS characterization of hirsutinolide and glaucolide sesquiterpene lactones: Fragmentation mechanisms and differentiation based on Na⁺/H⁺ adducts interactions in complex mixture

Abstract

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-H 2 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. KEYWORDShirsutinolides and glaucolides, ESI-QTofMS n analysis, ESI adducts interaction, fragmentation mechanism, computational study Correction added on 22 May 2020, after online publication: the data in Tables 1, 2, 3, 5 and the citation numbering throughout the article were corrected post publication. /journal/jms 915 916 DA SILVA ET AL. Journal of MASS SPECTROMETRY RESULTS AND DISCUSSION ESI-HRMS/MS analysis of pure compoundsAs depicted in Table 1, ESI(+)-HRMS analysis by direct injection indicated that the SL 1-4 afforded as base peak the ions at m/z 445.1473 (1), m/z 487.1570 (2), m/z 419.1327 (3), and m/z 461.1422 (4), corresponding to [M+Na] + and suggesting a strong affinity for Na + . Moreover, protonated ions [M+H] + were not detected for the hirsutinolide skeletons ( compounds 1 and 3), whereas [M+H] + ions were observed in extremely low abundance for glaucolides 2 (m/z 465.1740, 15%) and 4 (m/z 439.1620, 2%).DA SILVA ET AL.

Electrospray ionisation mass spectrometric behaviour of flavonoid 5‐O‐glucosides and their positional isomers detected in the extracts from the bark of Prunus cerasus L. and Prunus avium L.

“…The difference between the fragmentation of [M + H] + ions of genkwanin and prunetin is the formation of the product ions at m/z 124 and 257. The former is characteristic of genkwanin, the latter of prunetin 41–44 . The performed CID‐MS/MS experiments confirmed the structures of aglycones as shown in the Supporting Information.…”

Erratum: ESI‐QTof‐MS characterization of hirsutinolide and glaucolide sesquiterpene lactones: Fragmentation mechanisms and differentiation based on Na+/H+ adducts interactions in complex mixture

“…This erratum corrects the article by da Silva et al 1 Superscript numerals in Tables 1, 2, 3 and 5 were incorrectly captured as reference citations during production of this article. This caused the citation numbering throughout the article to be incorrect.…”

LC-ToF-ESI-MS Patterns of Hirsutinolide-like Sesquiterpenoids Present in the Elephantopus mollis Kunth Extract and Chemophenetic Significance of Its Chemical Constituents

“…To solve such problems, efforts have been focused on highly sensitive methods such as mass spectrometry (MS), which can help to identify most of the constituents of an extract. Pure compounds isolated from the studied plant could alternatively help to establish the MS fingerprint of this group of chemicals [ 9 ]. These standards could then provide an almost exhaustive chemical profile of a taxa [ 9 ].…”

“…Pure compounds isolated from the studied plant could alternatively help to establish the MS fingerprint of this group of chemicals [ 9 ]. These standards could then provide an almost exhaustive chemical profile of a taxa [ 9 ]. Accordingly, few reports are available in the literature on LC-MS characteristics of different sesquiterpenoid groups found in Elephantopus genus [ 9 ].…”

“…These standards could then provide an almost exhaustive chemical profile of a taxa [ 9 ]. Accordingly, few reports are available in the literature on LC-MS characteristics of different sesquiterpenoid groups found in Elephantopus genus [ 9 ]. In our attempt to elucidate the cytotoxicity and antibacterial properties of E. mollis , we isolated and identified/detected reported sesquiterpenoid lactones by LC-MS.…”