Solid complexes of pyridoxine with Mn(II) , Cd(II) and Zn(II) have
been isolated, as well as compounds containing Cu(II), Ni(II), Co(III),
Cd(II) and Zn(II), and pyridoxamine in various protonated forms. Infrared
spectra provide evidence for protonation at the pyridine nitrogen site in
the complexes, but not in the neutral vitamins and the complexes of
anionic pyridoxamine. Thus the complexed vitamins are in zwitterionic
forms, with chelation probably occurring through the phenolate oxygen and
either the amino or the hydroxy group at the 4' position.
Solid complexes of pyridoxine with Mn(II) , Cd(II) and Zn(II) have
been isolated, as well as compounds containing Cu(II), Ni(II), Co(III),
Cd(II) and Zn(II), and pyridoxamine in various protonated forms. Infrared
spectra provide evidence for protonation at the pyridine nitrogen site in
the complexes, but not in the neutral vitamins and the complexes of
anionic pyridoxamine. Thus the complexed vitamins are in zwitterionic
forms, with chelation probably occurring through the phenolate oxygen and
either the amino or the hydroxy group at the 4' position.
