Tyramine is a naturally occurring monoamine compound and trace amine derived from the amino acid tyrosine. Tyramine occurs widely in plants and animals, and is metabolized by the enzyme monoamine oxidase. Tyramine is an alpha-adrenergic agonist. Hypertension can occur, from ingestion of tyramine-rich foods in conjunction with monoamine oxidase inhibitors. The possibility that tyramine acts directly as a neurotransmitter was revealed by the discovery of a G protein-coupled receptor with high affinity for tyramine, called TAAR. It exhibits sympathomimetic effects by causing the release of endogenic norepinephrine. It has been used in mydriatic eyedrops. This has been said to reduce the intraocular pressure in rabbits and in some patients with open-angle glaucoma.

Porfiromycin is an N-methyl derivative of the antineoplastic antibiotic mitomycin-C initially isolated from Streptomyces ardus. Upon administration, the drug undergoes chemical or enzymatic reduction, followed by spontaneous loss of the tertiary methoxy (hydroxyl) group and formation of an aromatic indole system. Thus activated, porfiromycin generates oxygen radicals and alkylates DNA, producing interstrand cross-links and single-strand breaks at guanosine residues. Porfiromycin was tested in phase III for head and neck carcinoma, however, its development was terminated.

N,N-Dimethyl-5-Methoxytryptamine (aka 5-MeO-DMT) is a psychedelic of the tryptamine class. It is found in a wide variety of plant species, and a single psychoactive toad species, the Colorado River toad. Like its close relatives DMT and bufotenin (5-HO-DMT), it has been used as an entheogen in South America. It can also be found in the dart poison traditionally used by the Yanoama Indians of Upper Orinoco. It acts as a non-selective serotonin (5-HT) agonist. -MeO-DMT is O-demethylated by polymorphic cytochrome P450 2D6 (CYP2D6) to an active metabolite, bufotenine. 5-MeO-DMT is classified as a controlled substance in China, Australia, Sweden, Turkey, and the USA.

A-TRISACCHARIDE (or Blood group A trisaccharide), a core antigen fragment in ABO blood group system. It was found to be a major urinary carbohydrate depending on diet and blood type.