Analysis by fast atom bombardment mass spectrometry of 4,4-dicarboxy-5-(pyridoxyl-5'-phosphate)-proline, of 4-carboxy-5-(pyridoxyl-5'-phosphate)-proline and 4,4-dicarboxy-5-pyridoxylproline.
gamma-Carboxyglutamic acid (Gla) reacts easily and quantitatively with piridoxal-5'-phosphate in H2O at room temperature, to give the 4,4-dicarboxy-5-(pyridoxyl-5'-phosphate)-proline (1). This product has been characterized by fast atom bombardment (FAB) mass spectrometry, including the B/E linked scan technique, ultraviolet and 1H nuclear magnetic resonance (NMR) analysis. In order to support further on the structure of 1, the 4-monodecarboxyderivative (2), obtained by heating compound 1 at 100 degrees C for 30 min and the 5'-dephosphoderivative (3), obtained by enzymatic hydrolysis of 1 with alkaline phosphatase, were also analysed by FAB and 1H NMR techniques. FAB was shown to be the only adequate ionization technique to deal with such thermolabile and non-volatile compounds and could provide an elegant and fast method to detect Gla in biological matrices.
Capasso
R
R
Dipartimento di Chimica Organica e Biologica dell'Università di Napoli, Italy.
Pucci
P
P
Randazzo
G
G
Ritieni
A
A
Malorni
A
A
D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D011392:Proline / Q000031:analogs & derivatives* / Q000032:analysis; D011725:Pyridines / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet
D011725:Pyridines; C062805:4-carboxy-5-(pyridyloxy-5'-phosphate)proline; C062804:4,4-dicarboxy-5-(pyridoxyl-5'-phosphate)proline; C062806:4,4-dicarboxy-5-pyridoxylproline; D011392:Proline