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Desorption chemical ionization mass spectrometry of phorbol esters
Author(s) -
Takeda Naohito,
Suzuki Makoto,
Tatematsu Akira,
Ohigashi Hajime,
Koshimizu Koichi
Publication year - 1991
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.1200200108
Subject(s) - chemistry , mass spectrum , mass spectrometry , chemical ionization , reagent , moiety , isobutane , desorption , analytical chemistry (journal) , organic chemistry , chromatography , ionization , ion , catalysis , adsorption
Desorption chemical ionization (DCI) mass spectra of a series of phorbol di‐ and monoesters have been determined by mainly using ammonia and isobutane as reagent gases. The applicability of this mass spectrometric method in structural characterization of this class of compounds is discussed. The DCI (NH 3 ) mass spectra of phorbol diesters provided immediate confirmation of the molecular weight via an abundant adduction, [M + NH 4 ] + . The DCI (iso‐C 4 H 10 ) mass spectra more clearly afforded useful structural information with regard to the constitutent fatty acid attached to C‐12 or C‐13 and deacyloxy moiety. Therefore, a combination of the mass spectra with both reagent gases allows characterization of phorbol esters. The intensities of peaks in the DCI (iso‐C 4 H 10 ) mass spectra can be used to distinguish the phorbol‐12‐monoesters from the 13‐monoesters. It was found that hydrolysis of the phorbol 12,‐13‐diesters followed by DCI mass spectrometric analyses enabled the location of the longer‐chain acyl moiety at either C‐12 or C‐13 in the parent alcohol.