title: Fragmentation studies on monensin A and B by accurate-mass electrospray tandem mass spectrometry.
abstract: Monensin A and B were studied by electrospray ionisation tandem mass spectrometry (ESI-MS/MS) and the fragment ions were confirmed by accurate-mass measurements. Analyses were performed on both a quadrupole time-of-flight (QTOF) and a Fourier-transform ion cyclotron resonance (FTICR) mass spectrometer. The analysis revealed that fragment ions were produced by Grob-Wharton fragmentations and pericyclic rearrangements in addition to various simple neutral losses. A study of the protonated and sodiated sodium salt revealed different fragmentation pathways for these species, thus complementary structural information could be gained. A complete fragmentation pathway of monensin A and B protonated sodium salt [(M-H+Na)+H])+) and sodiated sodium salt [(M-H+Na)+Na](+) is proposed. MS(3) analysis confirmed the separate fragmentation pathways.
authors.affiliation: University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK.
authors.forename: Norberto P
authors.initials: NP
authors.lastname: Lopes
authors.forename: Christian B W
authors.initials: CB
authors.lastname: Stark
authors.forename: Hui
authors.initials: H
authors.lastname: Hong
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Gates
authors.forename: James
authors.initials: J
authors.lastname: Staunton
mesh_terms: D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry; D008985:Monensin / Q000031:analogs & derivatives* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: C042849:monensin B; D008985:Monensin