Studies on Bile Pigments I. Separation of Natural Indirect Bilirubins

Descriptions are carried on the method how to separate the indirect bilirubin from the chloroform extracts of the dried dog's gallbeadder bile by adsorption chromatography. 1. The optimal concentrations of the bilirubin content were 2 to 4 mg/100 ml when 1 ml of the sample was adsorbed on the Tswett tube of about 10 mm diameter. 2. Though several zones of the indirect bilirubin were separated on the column of silica gel when developed with various solvents, these zones were proved to be mingled with some oxidized or other intermediate products and the separation like this was thought to owe to the activity of the adsorbents. 3. The chromatogram of the crystalline bilirubin resembled to the one formed by the indirect bilirubin in the chloroform extracts. 4. The chromatogram of the chromatographically separated indirect bilirubin was similar to the former. 5. The absorption maxima of a chloroform solution of the natural indirect bilirubin existed at 450 mμ in the visible range, and it was the same as the maxima of the crystalline bilirubins.