Characterization of isomeric cationic porphyrins with beta-pyrrolic substituents by electrospray mass spectrometry: the singular behavior of a potential virus photoinactivator.
Electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (ESI-MS/MS) have been used to differentiate the 2- and 4-methylpyridyl isomers of free-base and metallated cationic beta-vinylpyridylporphyrins. The analysis by ESI-MS/MS of the deuterated analogs and semiempirical calculations of structural and electronic parameters were also undertaken. The two free-base isomers are easily differentiated by ESI-MS/MS but the presence of a metallic center renders differentiation of the metallated isomers less effective. The data acquired show that of all the studied compounds, the free-base 2-methylpyridyl isomer, which was operative in the in vitro photoinactivation of Herpes simples virus, has a different gas-phase behavior. Local distortion of the macrocycle due to the presence of the beta-vinylpyridyl substituent occurs for all the compounds, but a different electron density distribution can account for the observed gas-phase behavior of this potential virus photoinactivator.
Izquierdo
Raul A
RA
Mass Spectrometry Laboratory, Department of Chemistry, University of Aveiro, Campus de Santiago, Aveiro, Portugal.
Barros
Cristina M
CM
Santana-Marques
M Graça
MG
Ferrer-Correia
A J
AJ
Silva
Eduarda M P
EM
Giuntini
Francesca
F
Faustino
Maria A F
MA
Tomé
João P C
JP
Tomé
Augusto C
AC
Silva
Artur M S
AM
Neves
Graça P M S
GP
Cavaleiro
J A S
JA
Peixoto
Andreia F
AF
Pereira
Mariette M
MM
Pais
Alberto A C C
AA
D000998:Antiviral Agents / Q000032:analysis / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D007536:Isomerism; D010777:Photochemistry; D011166:Porphyrins / Q000032:analysis / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014753:Vinyl Compounds / Q000032:analysis / Q000737:chemistry*; D038301:Virus Inactivation
D000998:Antiviral Agents; D002412:Cations; D011166:Porphyrins; D014753:Vinyl Compounds; C409084:tetraphenylporphyrin