. "indols" . . "1H-Indole" . . . . "Indole" . . . "C₈H₆N" . . . . . "benzene and pyrrole ring" . . . . "dihydroxyindole" . "1-benzazole" . "indole ring" . . . . . . . . "Indoles" . "Indole" . "indolic" . "indole" . . . . . . . . . "2,3-Benzopyrrole, ketole," . "indol" . . . . "Benzopyrrole or indole" . . . "oxidation" . . . . . "indoles" . . .