Disturbance of bilirubin metabolism in the intestine in liver diseases was investigated from the oxidation products of mesobilirubinogen. Feces were obtained from five normal subjects, five cases with chronic hepatitis, five cases with liver cirrhosis and three cases with hemolytic jaundice. The oxidation products of mesobilirubinogen were prepared by Stoll's thin layer chromatography after extraction procedure from feces by Watson. The oxidation products were divided into two groups, verdins (glaucobilins) and violins (mesobiliviolins). The verdins were identified by nuclear magnetic resonance (NMR) spectra and mass spectrometry as glaucobilin isomers. The results were as follows; 1) Glaucobilin Ⅲα, Ⅸα and ⅩⅢα dimethylester were separated ...