IV. Formation of (Laevorotatory) Stercobilin from Mesobilirubinogen in Human Feces. ∗

Abstract

Summary and Conclusions

1. The oral or intraduodenal administration of mesobilirubinogen resulted in an increased excretion of stercobilin in the feces. 2. The incubation of mesobilirubinogen with normal feces, or with acholic feces plus bile resulted in formation of stercobilin. Incubation with acholic feces alone resulted in no change; urobilin IX,a was subsequently isolated. 3. Mesobilirubinogen was not converted to stercobilin in the 3 urine samples studied. It is believed that mesobilirubinogen is the primary chromogen or urobilinogen formed by bacterial reduction of bilirubin. The further elaboration of d-urobilin requires bile, while that of stercobilin requires bile and feces.