15770-19-1Relevant articles and documents
Induction of wavelength-dependent photochemistry in bilirubins by serum albumin
McDonagh, Antony F.,Agati, Giovanni,Lightner, David A.
, p. 649 - 660 (2007/10/03)
Quantum yields for Z ? E photoisomerization of the natural bi-chromophore bilirubin IXα in ammoniacal methanol solution were found to vary with excitation wavelength, whereas no variation (within experimental error) was observed for xanthobilirubic acid and for symmetrically substituted bilirubins (bilirubin IIIα, bilirubin XIIIα, and mesobilirubin XIIα) in the same solvent. The quantum yield for Z ? E photoisomerization of xanthobilirubic acid bound to human serum albumin was also invariant with excitation wavelength. In contrast, quantum yields for Z ? E photoisomerization of the symmetrically-substituted bilirubins did show marked excitation wavelength dependency when they were bound to human serum albumin. These results show that quantum yields for Z ? E photoisomerization of bilirubins are markedly sensitive to protein binding and to the nature of pyrrole ring β-substituents. They also demonstrate that wavelength-dependent photochemistry is characteristic of bilirubins with non-identical pyrromethenone chromophores, as expected from exciton coupling theory, and that complexation with albumin induces wavelength-dependent photochemistry in symmetrically substituted bilirubins.
Xanthobilirubic Acid and Its Amides. Synthesis, Spectroscopy, and Solution Structures
Lightner, D. A.,Ma, J.-S.,Adams, T. C.,Franklin, R. W.,Landen, G. L.
, p. 139 - 144 (2007/10/02)
Xanthobilirubic acid, 5--2,4-dimethyl-1H-pyrrol-3-propanoic acid, its methyl ester, amide, N-methylamide and dimethylamide, and kryptopyrromethenone have been synthesized and characterized spectroscopically.In d6-DMSO solution all pyrromethenones were monomeric, with lactam and pyrrole N-Hs H-bonded to solvent.In deuteriochloroform, the pyrromethenones preferred a dimeric form, with intramolecular H-bonding between the lactam C=O of one unit and the lactam and pyrrole N-Hs of the second.
