An Overview of Bilirubin Chemistry

Abstract

“From gall disease, that is from the yellow jaundice cometh great evil; it is of all disease most powerful, when there wax within a man, unmeasured humors; these are the tokens; that the patient’s body all becometh bitter and as yellow as good silk; and under the root of his tongue there be swart veins and pernicious, and his urine is yellow”(1). The yellow pigment referred to in this vivid eleventh-century Anglo-Saxon description of cirrhosis was first isolated in crystalline form by Virchow in 1847(2), and named bilirubin by Stadeler in 1864(3). Its structure was determined by Siedel and Fischer in 1933(4) and confirmed by total synthesis by Fischer and Plieninger in 1943(5) and more recently by Plieninger et al(6). Much of the basic chemistry of the pigment was elucidated more than two decades ago, principally by the Fischer school. And today, despite the fact that bilirubin is a metabolic waste-product of no practical utility other than its diagnostic value, scientific interest in the pigment continues unabated. In the past two to three years alone bilirubin has been mentioned in over 1600 publications, and of these about 400 specifically with some aspect of the chemistry or biochemistry of the molecule. The areas of bilirubin chemistry and biochemistry which appear to have received the most attention in recent years are the mechanism of bilirubin formation, the mechanism of bilirubin conjugation and excretion, the nature of bilirubin conjugates, bilirubin-protein complexes, and the photochemistry of bilirubin.