Carnegine

Carnegine, also known as pectenine, DMMM-4, or 6,7-dimethoxy-1,2-dimethyl-1,2,3,4-tetrahydroisoquinoline, is a tetrahydroisoquinoline and cyclized phenethylamine alkaloid found in Carnegiea gigantea, Pachycereus pringlei, and other cacti.
It is known to be pharmacologically active, including acting as a relatively potent monoamine [oxidase inhibitor], specifically of monoamine oxidase A but not of monoamine oxidase B, producing strychnine-like convulsions in animals, and having other actions and effects. Carnegine and similar alkaloids might potentiate the effects of mescaline and related compounds like N-methylmescaline via their MAOI activity.
The compound was first isolated in 1901 and its structure and synthesis were established in 1929.