Fragmentation of trimethoprim and other compounds containing alkoxy-phenyl groups in electrospray ionisation tandem mass spectrometry.
This work describes electrospray ionisation tandem mass spectrometry studies of trimethoprim and a series of structurally similar compounds containing alkoxy-phenyl groups; using accurate mass measurement to confirm the proposed fragmentations. Radical cations were observed in the spectra obtained for some of the compounds, as well as uncommon fragmentations showing losses of CH4 and C2H6, whereas other compounds showed the formation of even electron ions. Possible structures for the fragment ions have been proposed and explanations for the different types of fragmentations based on the structures of the compounds. In addition an alternate structure for a fragment ion previously reported for tandem mass spectrometry of trimethoprim has been proposed, based on accurate mass measurement.
Eckers
Christine
C
GlaxoSmithKline, Analytical Sciences, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, UK.
Monaghan
John J
JJ
Wolff
Jean-Claude
JC
D000438:Alcohols / Q000032:analysis / Q000737:chemistry; D000473:Alkanes / Q000032:analysis / Q000737:chemistry; D000814:Aniline Compounds / Q000032:analysis / Q000737:chemistry; D001549:Benzamides / Q000032:analysis / Q000737:chemistry; D004345:Drug Industry / Q000295:instrumentation / Q000379:methods; D005493:Folic Acid Antagonists / Q000032:analysis* / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D014295:Trimethoprim / Q000032:analysis* / Q000737:chemistry
D000438:Alcohols; D000473:Alkanes; D000814:Aniline Compounds; D001549:Benzamides; D005493:Folic Acid Antagonists; C031246:3,4,5-trimethoxybenzamide; D014295:Trimethoprim