Pinoline is a methoxylated tryptoline

Tryptoline

Tryptoline, also known as tetrahydro-β-carboline and tetrahydronorharmane, is a natural organic derivative of beta-carboline. It is an alkaloid chemically related to tryptamines...

  that occurs in the pineal gland

Pineal gland

The pineal gland is a small endocrine gland in the vertebrate brain. It produces the serotonin derivative melatonin, a hormone that affects the modulation of wake/sleep patterns and seasonal functions...

 during the metabolism of melatonin

Melatonin

Melatonin , also known chemically as N-acetyl-5-methoxytryptamine, is a naturally occurring compound found in animals, plants, and microbes...

. Its chemical names are 5-methoxytryptoline and 6-methoxy-1,2,3,4-tetrahydro-β-carboline (6-MeO-THBC). The biological activity of this molecule is of interest as a potential free radical scavenger (antioxidant

Antioxidant

An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

), similar to that function of melatonin. It also acts as an endogenous MAOI.