Characterization of dinitroporphyrin zinc complexes by electrospray ionization tandem mass spectrometry. Unusual fragmentations of β‐(1,3‐dinitroalkyl) porphyrins

Abstract

The zinc complexes of diaryl bis(p-nitrophenyl)porphyrins and beta-(1,3-dinitroalkyl)tetraphenylporphyrins were studied by electrospray ionization (ESI) tandem mass spectrometry (MS/MS). All porphyrins showed the protonated molecule under ESI conditions. The protonated molecules were induced to fragment and the corresponding ESI tandem mass spectra were analysed. Porphyrins with two p-nitrophenyl groups showed, as expected, characteristic fragmentations including either loss of one nitro group, as the major fragment of the tandem mass spectra, and loss of both nitro groups. In contrast, MS/MS of the beta-(1,3-dinitroalkyl)porphyrins provided interesting and unexpected results such as the absence (or in insignificant abundance) of the ions formed by loss of one nitro group. However, these porphyrins show an abundant fragment due to combined loss of the two nitro groups. Also, the typical beta-cleavage of the alkyl chain is not observed per se, only when combined with loss of HNO2 or *NO2. Instead, alpha-cleavage, with loss of the beta-pyrrolic substituent, is the most favourable process.

Electrospray tandem mass spectrometry of new porphyrin amino acid conjugates

“…Nowadays, it is known that mass spectrometry can give significant structural information about porphyrinic derivatives 10–18. Product ions observed in spectra obtained by tandem mass spectrometry (MS/MS) of porphyrins allowed the identification of the structural features of the peripheral substituents.…”

“…Product ions observed in spectra obtained by tandem mass spectrometry (MS/MS) of porphyrins allowed the identification of the structural features of the peripheral substituents. Although MS/MS spectra give information of the structural features of the peripheral phenyl substituents of meso ‐tetraarylporphyrins, there has not been much work done in this area 13, 15–17. Furthermore, MS/MS can be a unique tool when a low amount and/or a not very pure sample is available for analysis, and also in the study of mixtures 10.…”

Observation of phenyl-fused porphyrinoids during the ESI mass spectrometric analysis of meso-pentafluorophenyl-substituted porphyrin and corrole

“…Electrospray ionization (ESI) mass spectrometry (MS) is becoming a popular technique for the analyses of porphyrins [25][26][27][28][29][30][31][32][33][34][35].…”

Characterization of isomeric cationic porphyrins with β-pyrrolic substituents by electrospray mass spectrometry: The singular behavior of a potential virus photoinactivator

“…In particular, the Herpes simplex virus is one of the most common agents responsible for viral infections in man [5]. From preliminary virus inactivation studies carried out with Herpes simplex virus type 1 (HSV-1) using the cationic porphyrins 1 and 2 (Scheme 1), we have observed that despite their structural resemblance and their similar photocytotoxicity profiles, Compound 1 was very effective in the photoinactivation of the virus, whereas Compound 2 displayed no virucidal effect in the same conditions [6].Electrospray ionization mass spectrometry (ESI-MS) was successfully applied to characterize porphyrins as early as 1991 [7] and both ESI-MS [8 -11] and tandem mass spectrometry (ESI-MS/MS) [12,13] have been used to study neutral and cationic porphyrins since then. We wanted to know if the two porphyrin isomers, 1 and 2, could be differentiated by ESI-MS/MS and if the informa-…”

“…Electrospray ionization mass spectrometry (ESI-MS) was successfully applied to characterize porphyrins as early as 1991 [7] and both ESI-MS [8 -11] and tandem mass spectrometry (ESI-MS/MS) [12,13] have been used to study neutral and cationic porphyrins since then. We wanted to know if the two porphyrin isomers, 1 and 2, could be differentiated by ESI-MS/MS and if the informa-tion obtained on their gas-phase behavior could be relevant to understand their virucidal properties.…”