title: Black pigment or polybilirubinate gallstones: composition and formation.
abstract: Black pigment, extracted from gallstones from patients, has been characterized as polybilirubinate. A similar material with the same physical properties was synthesized from bilirubin. The properties of black pigment are described. A mechanism for black pigment formation is postulated, and the possible relationship of this pigment to the formation of gallstones is discussed.
mesh_terms: D001663:Bilirubin / Q000031:analogs & derivatives* / Q000032:analysis; D002769:Cholelithiasis / Q000378:metabolism*; D004577:Electron Probe Microanalysis; D006801:Humans; D013058:Mass Spectrometry; D013055:Spectrophotometry, Infrared
chemical_list: C028922:polybilirubinate; D001663:Bilirubin