Studies on bile pigments V. A method to isolate indirect bilirubin

For the purpose of obtaining the dibasic acid indirect bilirubin in a pure state from the dried canine cholecystic bile, an optimal developing solvent was selected by paper partition chromatography as a preliminary experiment, and it was isolated on cellulose column as an applied experiment. 1. The dibasic acid indirect bilirubin was separable at the starting point in a pure state by paper chromatography under development with the top layer of a n-butanol, acetic acid, water mixture (4:1:5). 2. The dibasic acid indirect bilirubin formed a fixed band at the upper starting place on cellulose column under development with the top layer of a n-butanol, acetic acid, water mixture (4:1:5), and no other substance could be detected there. 3. The dibasic acid indirect bilirubin existing in the fixed band could be eluted out into chloroform with a 1% acetic acid solution. An orange yellow powder was obtained from the eluate by evaporating the solvent in vacuo. 4. Thus separated orange yellow powder agreed well with the crystalline bilirubin in the solubility into organic or inorganic solvents and in the spectrochemical characteristics as well as in the chemical properties.