Premium
Differentiation of 4α‐ and 4β‐phorbol diesters by fast atom bombardment mass spectrometry
Author(s) -
Takeda Naohito,
Tatematsu Akira,
Suzuki Makoto,
Ohigashi Hajime,
Koshimizu Koichi
Publication year - 1993
Publication title -
biological mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1052-9306
DOI - 10.1002/bms.1200220407
Subject(s) - fast atom bombardment , chemistry , mass spectrometry , dissociation (chemistry) , ion , mass spectrum , structural isomer , electron ionization , ionization , collision induced dissociation , fragmentation (computing) , atom (system on chip) , spectral line , chemical ionization , crystallography , tandem mass spectrometry , stereochemistry , organic chemistry , chromatography , computer science , operating system , physics , astronomy , embedded system
Fast atom bombardment (FAB) mass spectra of a series of stereoisomeric pairs of 4α‐ and 4β‐phorbol diesters were determined in order to evaluate the possibility of differentiation between both isomers. A key feature in differentiating 4α‐ isomers ( cis fusion of A/B ring in a tigliane nucleus) from 4β‐ isomers ( trans A/B) is that the m/z 271 ion is only present in the FAB mass spectra of 4α‐ isomers, whereas this ion is virtually absent in the 4β‐isomers. Analogously, the m/z 255 ion is only seen in the spectra of 4‐deoxy‐4α‐phorbol diesters. The formation of m/z 271 ( m/z 255) is characteristic with FAB ionization, but not with electron impact or chemical ionization. High‐resolution, metastable decomposition and collision‐activated dissociation experiments were carried out to elucidate the ion structure of m/z 271, and the mechanistic rationale for the formation was discussed.