metabolic pathway of secondary metabolites indole and ipecac alkaloid biosynthetic pathway PW:0000253 Those metabolic reactions involved in the synthesis of indole and ipecac. Indole is a heterocyclic compound, obtained from coal tar, and produced by the decomposition of tryptophan in the intestine, being partly responsible for the peculiar odor of the feces. It is also found in cultures of Vibrio cholerae and other bacteria; a color test for its production is used in classifying enteric bacteria. Ipecac is derived from the dried rhizome and roots of Cephaelis ipecacuanha or of C. acuminata. It is a mixture of alkaloids, primarily emetine and cephaelin. pathway