N-propyl-L-tryptophan is an amino acid derivative. It is the N-propyl homologue of L-abrine (N-methyl-L-tryptophan), and is structurally similar to hypaphorine (L-tryptophan betaine) . L-abrine is a biosynthetic precursor to the ergot alkaloids in the ergot fungus. It is possible that N-propyl-L-tryptophan may even be biosynthesized by the ergot fungus to produce 6-propyl-6-nor-substituted ergot alkaloids, however this is purely speculative.
N-propyl-L-tryptophan also bears structural resemblance to NPT (N-propyltryptamine) and MPT (N,N-methylpropyltryptamine). It is unknown if it were to act as a prodrug for NPT, or if it even has any bioavailability (that is, if it can pass the blood-brain barrier).
This compound is NOT for human consumption or in vivo research and is strictly for other research purposes only. Available as the free zwitterion.
 – Shulgin, Alexander. “DMT & Tryptophan.” DMT | Ask Dr. Shulgin Online, Center for Cognitive Liberty and Ethics, 19 Sept. 2002, www.cognitiveliberty.org/shulgin/adsarchive/dmt.htm.