Mass spectrometric studies of selected coumarins and psoralens. I—negative ions

Abstract

An investigation of the negative-ion chemistry of 13 coumarin and three psoralen compounds is reported. Negativeion chemical ionization was effected using 0-' and OH-as the reagent ions; it was found that 0-' leads preferably to ( M -H + 01whereas OHmainly furnishes ( M -HI -. The results of metastable anion fragmentation and collision-induced dissociation of mass-selected anions are presented. 4Coumarin, 1 Scheme 1. Structure of coumarin (1) with substituent numbering system.

Negative Ion Electrospray Ionization Mass Spectrometry and Computational Studies on Substituted 7-Hydroxycoumarins

“…7,8 Although coumarins have been widely investigated in synthetic studies, and in medicinal use, 9,10 only a few articles examine their mass spectrometric fragmentations, and none have attempted molecular modeling of their mass fragments. Some coumarin derivatives have been studied by negative ion chemical ionization (NIcI), 11,12 and demethylation of the methoxy-substituted coumarins has been demonstrated. Positive and negative electrospray ionization (ESI) studies have also been done, but these have mainly concerned 4-hydroxycoumarin derivatives.…”

Low‐energy collision‐induced dissociation tandem mass spectrometry of 7‐acetonyloxycoumarins

“…[12] Negative-ion chemical ionization (CI) of selected coumarins and psoralens with metastable ion fragmentation or collision-induced dissociation (CID) tandem mass spectrometry (MS n ) exhibited similar characteristics to EI. [13] Cappiello and co-workers used high-performance liquid chromatography (HPLC) combined with the EI-MS instrument via a particle beam interface to successfully study eighteen naturally occurring coumarins from the Smyrnium perfoliatum extract. [14] More recently, electrospray ionization (ESI) has been employed in the MS and MS n studies of coumarins.…”

Electrospray mass spectrometry in the differentiation of some isomeric trimethylfurocoumarins

“…Negative ion spectra, obtained by electron attachment, show the production of highly specific ions related to the substituent position on the benzene ring. Further studies applied collisional experiments, performed using an ion trap, in the characterization of furano‐ and pyranocoumarins 16. The operating characteristics of the ion trap, mainly the step‐by‐step energy deposition occurring during the ion activation phase,17 appear to be well suited to the characterization of the different isomers.…”