Transition metal complexes of bilirubin and biliverdin were studied spectrophotometrically, in DMSO and in a boric acid-NaOH buffer mixture at pH 10.5. In the zinc(II) and cadmium(II)- bilirubin systems, 2:1 complexes are formed. Both in aqueous and in DMSO medium, the copper(II) ion oxidizes bilirubin to biliverdin. With all three metal ions, biliverdin forms 1:1 complexes, the stabilities of which are higher than those of the corresponding bilirubin complexes. Accordingly, these metal ions accelerate the oxidative transformations of bilirubin.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry