Studies on the Hydroxylation of the Benzene Moiety of the Indole Nucleus of Indole Compounds

Abstract
The endproduct of indolebutyric acid by rabbit liver enzyme (188,000xg supernatant of the tris buffer (pH 7.8) homogenates) was isolated from the 4% HClO4 filtrate of the reaction mixture, and identified as 6-hydroxyindole-3-butyric acid, which gave a reddish diazo reaction in acid.