Gaseous iron-protoporphyrin-IX (heme) ions, Fe(PP-IX)+, obtained by electrospray ionization of a methanol solution of hemin chloride, are allowed to react with ozone forming a species that is tentatively assigned the structure of an oxo-complex, namely an iron(IV)-oxo protoporphyrin IX radical cation species, (PP-IX)+•FeIV=O. This species, representing the naked core of the putative active oxidant (Compound I) of heme enzymes, is characterized by its reactivity behavior in FT-ICR mass spectrometry, performing as an active O-atom donor. A quite distinct reactivity is displayed by an isomeric species holding the additional oxygen on the porphyrin frame, Fe(PP-IX(O))+. This isomer undergoes a ligand addition process as previously observed for Fe(PP-IX)+.
Compound I of Naked Heme (Iron-Protoporphyrin IX) / Crestoni, Maria Elisa; Fornarini, Simonetta. - In: INORGANIC CHEMISTRY. - ISSN 0020-1669. - STAMPA. - 46:(2007), pp. 9018-9020. [10.1021/ic700698d]
Compound I of Naked Heme (Iron-Protoporphyrin IX)
CRESTONI, Maria Elisa;FORNARINI, Simonetta
2007
Abstract
Gaseous iron-protoporphyrin-IX (heme) ions, Fe(PP-IX)+, obtained by electrospray ionization of a methanol solution of hemin chloride, are allowed to react with ozone forming a species that is tentatively assigned the structure of an oxo-complex, namely an iron(IV)-oxo protoporphyrin IX radical cation species, (PP-IX)+•FeIV=O. This species, representing the naked core of the putative active oxidant (Compound I) of heme enzymes, is characterized by its reactivity behavior in FT-ICR mass spectrometry, performing as an active O-atom donor. A quite distinct reactivity is displayed by an isomeric species holding the additional oxygen on the porphyrin frame, Fe(PP-IX(O))+. This isomer undergoes a ligand addition process as previously observed for Fe(PP-IX)+.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
