Indole
An indole is an organic molecular structure, consisting of the bicyclic of benzene and a pyrrole.
Indoles are found in many organisms, and many indoles are biologically active.
Indole is a precursor of the widely-occurring amino acid tryptophan.
Some alkaloids are indoles, including the hallucinogenic tryptamines
psilocybin, DMT, and LSD. The structure is also found in many naturally-occurring human neurotransmitters, such as serotonin.
An indole could be described as the union of a 6-membered benzene ring with a five-membered pyrrole ring. The pyrrole has one nitrogen atom present.
Although the Nitrogen atom on the pyrrole has a lone pair, it will not readily accept protons: it is a secondary amine, and moreover the lone pair is delocalised into the aromatic system.
The name indole is derived from indigo, a blue pigment obtained from some plant species.
The indigo molecule comprises two indole units joined together.
