ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Quaternary methoiodides of tetrahydroprotoberberine (THB) alkaloids (1-8) tend to undergo preionization degradation in the mass spectrometer at elevated temperatures. Different reaction pathways have been found in relation to the structure of the substance studied. Permethylated alkaloids, e.g. tetrahydropalmatine-CH3I (8), give predominantly the Hofmann degradation intermediates and the fragment ions derived therein, while the alkaloids with free phenolic group(groups), as exemplified by scoulerine-CH3I (1), show a greater tendency to be methylated by an intermolecular CH3 transfer mechanism: The latter process has been systematically studied and the mechanism substantiated through comparison of the spectra of analogous series, B/E linked scan and CD3 labelling. Similar behaviour has been observed in bisbenzyltetrahydroisoquinoline alkaloids.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210191204
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