Differentiation between 3, 4- and 4, 15-Epoxyeudesmanolides by Electrospray Ionization Tandem Mass Spectrometry. (6th November 2017)

• Record Type: Journal Article
• Authors: Dias, Herbert Júnior; Stefani, Ricardo; Tomaz, José Carlos; Vessecchi, Ricardo; Crotti, Antônio Eduardo Miller
• Other Names: Rosenberg Erwin Academic Editor.
• Is Part Of: Journal of analytical methods in chemistry. Volume 2017(2017)
• Publication Date: 2017-11-06
• Subjects: Chemistry, Analytic -- Periodicals; Chemistry, Analytic -- Technique -- Periodicals; 543.05
• DOI: 10.1155/2017/7921867
• Languages: English
• ISSNs: 2090-8865

Abstract

Abstract : We investigated the fragmentation of the eudesmanolide-type sesquiterpene lactones 1 α -(4-hydroxymethacryloyloxy)-3 α, 4 α -epoxy-8 α -hydroxyeudesm-11(13)-6 α, 12-olide (1 ) and 1 α -(2, 3-epoxyangeloyloxy)-4 α, 15-epoxy-8 α -hydroxyeudesm-11(13)-6 α, 12-olide (2 ) by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The elimination of the different ester substituent at C(1) directly from protonated 1 and 2 (A ) led to the formation of two regioisomer product ions B (A − RCO2 H). Further fragmentation of B resulted from consecutive eliminations of H2 O and CO molecules. However, we identified four product ions that allowed for the differentiation between 3, 4- and 4, 15-epoxyeudesmanolides. The formation of these diagnostic ions was associated with the C(3)–O bond of compound 1, which propitiates the participation of the lone pair of the oxygen epoxide in the formation of B through a Grob-Wharton-type fragmentation, then resulting in an alternative fragmentation pathway. These data can be useful for the fast differentiation between epoxyeudesmanolide regioisomers directly from Dimerostemma extracts by liquid chromatography-tandem mass spectrometry (LC-MS/MS), as an alternative to NMR, or even for quantitation studies of these compounds using multiple reaction monitoring (MRM) scan.