Identification of Isomers Differing from 9,α,in the Early Labelled Bilirubin of the Bile. ∗

Abstract

Conclusions

1. ¹⁴C-bilirubin; isolated from bile of a dog within the first few hours after administration of ¹⁴C-ALA, on oxidation with KMnO₄ yields a significant amount of α,α-dicarboxylic pyrrolic acid I as well as II, thus revealing that this early labelled bili-rubin contains a fraction of an isomer other than 9,α, the principal bilirubin of the bile. 2. Similar oxidation of large samples of commercial bilirubin (>200 mg) also produces acid I, although in very small proportion with II, thus indicating presence of an isomer other than 9,α, in a correspondingly small proportion of the total bilirubin of the bile.