A systematic investigation of the fragmentation pattern of two furanoheliangolide C-8 stereoisomers using electrospray ionization mass spectrometry

Author(s)

Sartori, Lucas Rossi ^{[1, 2]} ; Vessecchi, Ricardo ^{[3, 2]} ; Humpf, Hans-Ulrich ^[1] ; Da Costa, Fernando Batista ^[4] ; Lopes, Norberto Peporine ^[2]

Affiliation

^[1] Univ Munster, Inst Food Chem, D-48149 Munster - Germany

^[2] Univ Sao Paulo, Nucleo Pesquisa Prod Nat & Sintet, Dept Quim & Fis, Fac Ciencias Farmaceut Ribeirao Preto, BR-14040903 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[4] Univ Sao Paulo, Sch Pharmaceut Sci Ribeirao Preto, Dept Pharmaceut Sci, AsterBioChem Res Team, Lab Pharmacognosy, BR-14040903 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: RAPID COMMUNICATIONS IN MASS SPECTROMETRY; v. 28, n. 7, p. 723-730, APR 15 2014.
• Web of Science Citations: 9

Abstract

RATIONALE Budlein A is a sesquiterpene lactone (STL) with some reported biological activities. Pre-clinical studies to identify in vivo metabolites often employ hyphenated techniques such as liquid chromatography/tandem mass spectrometry (LC/MS/MS). It is also possible to use the fragmentation pattern obtained by Collision-Induced Dissociation (CID) and Higher Energy Collision-Induced Dissociation (HCD) to distinguish between the stereoisomers budlein A and centratherin. METHODS The experiments were carried out in the positive mode using four different spectrometers with an electrospray ionization (ESI) source: (a) Waters ACQUITY((R)) TQD triple quadrupole mass spectrometer (QqQ), (b) AB Sciex API 4000 QTrap((R)) (QqQ), (c) Bruker Daltonics micrOTOF (TM)-Q II (time-of-flight, QTOF), and (d) Thermo Scientific LTQ Orbitrap XL hybrid FTMS (Fourier transform mass spectrometer). Computational chemistry studies helped to identify the protonation sites. The B3LYP/6-31G(d) model furnished the equilibrium geometries and energies. RESULTS The stereochemistry (alpha- or beta-orientation) of the centratherin and budlein A side-chain esters influences the fragmentation pattern recorded on QqQ, QTOF, and Orbitrap-HCD. On QqQ, centratherin releases the side chain, to generate the m/z 275 fragment ion, whereas budlein A gives the m/z 83 fragment ion. On QTOF and Orbitrap-HCD, only budlein A affords the m/z 293 and 83 fragment ions, respectively. CONCLUSIONS The data suggest that proton migration governs the fragmentation pathways under alpha- or beta-orientation. The difference in the QqQ, QTOF, and Orbitrap-HCD spectral profiles of each isomer can help to distinguish between centratherin and budlein A using MS/MS, which becomes an alternative to nuclear magnetic resonance (NMR) analysis. Copyright (c) 2014 John Wiley \& Sons, Ltd. (AU)

• FAPESP's process: 10/07413-0 - In vivo and in vitro evaluation of budlein A metabolism and the determination of pharmacokinetic parameters
• Grantee: Lucas Rossi Sartori
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 09/51812-0 - Development of a platform for the study of in vitro and in vivo metabolism of natural products, a need for pre-clinical testing system
• Grantee: Norberto Peporine Lopes
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants