Fourier transform infrared spectroscopy demonstrates the reactivity of the protonated carboxyl group of the acid salt of calcium bilirubinate

R. D. Soloway, J. G. Wu, D. F. Xu, Y. F. Zhang, D. K. Martini, N. K. Hong, R. S. Crowther

Research output: Contribution to journalArticle

2 Scopus citations


Calcium bilirubinate is a major salt in pigment gallstones. Bilirubin IX (H2BR) is a tetrapyrrole with 1 propionic acid side chain on both the B and C rings. A striking feature is the strong intramolecular hydrogen bonding of both carboxyl groups as determined by x-ray diffraction. This greatly reduces aqueous solubility. Much less is known about the structure of the salts of calcium bilirubinate since single crystals have not been formed. One or both carboxyl groups of bilirubin may coordinate with calcium in stone, forming the acid or neutral salt.

Original languageEnglish (US)
Pages (from-to)262-263
Number of pages2
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - Dec 1 1989


ASJC Scopus subject areas

  • Applied Mathematics
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Computer Science Applications

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