Molecules (Mar 2023)

Insights into the Structures of Bilirubin and Biliverdin from Vibrational and Electronic Circular Dichroism: History and Perspectives

  • Giovanna Longhi,
  • Simone Ghidinelli,
  • Sergio Abbate,
  • Giuseppe Mazzeo,
  • Marco Fusè,
  • Stefan E. Boiadjiev,
  • David A. Lightner

DOI
https://doi.org/10.3390/molecules28062564
Journal volume & issue
Vol. 28, no. 6
p. 2564

Abstract

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In this work we review research activities on a few of the most relevant structural aspects of bilirubin (BR) and biliverdin (BV). Special attention is paid to the exocyclic C=C bonds being in mostly Z rather than E configurations, and to the overall conformation being essentially different for BR and BV due to the presence or absence of the double C=C bond at C-10. In both cases, racemic mixtures of each compound of either M or P configuration are present in achiral solutions; however, imbalance between the two configurations may be easily achieved. In particular, results based on chiroptical spectroscopies, both electronic and vibrational circular dichroism (ECD and VCD) methods, are presented for chirally derivatized BR and BV molecules. Finally, we review deracemization experiments monitored with ECD data from our lab for BR in the presence of serum albumin and anesthetic compounds.

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