Several alkaloid

Alkaloid

Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...

s that function as monoamine oxidase inhibitor

Monoamine oxidase inhibitor

Monoamine oxidase inhibitors are a class of antidepressant drugs prescribed for the treatment of depression. They are particularly effective in treating atypical depression....

s (MAOIs) are found in the seed

Seed

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s of Peganum harmala (also known as Harmal

Harmal

Harmal is a plant of the family Nitrariaceae, native from the eastern Mediterranean region east to India. It is also known as Wild Rue or Syrian Rue because of its resemblance to plants of the rue family....

or Syrian Rue), including harmine

Harmine

Harmine is a fluorescent harmala alkaloid belonging to the beta-carboline family of compounds. It occurs in a number of different plants, most notably the Middle Eastern plant harmal or Syrian rue and the South American vine Banisteriopsis caapi...

, harmaline

Harmaline

Harmaline is a fluorescent psychoactive indole alkaloid from the group of harmala alkaloids and beta-carbolines. It is the reduced hydrogenated form of harmine.-Occurrence in nature:...

, and harmalol, which are members of a group of substances with a similar chemical structure collectively known as harmala alkaloids. These alkaloids are of interest for their use in Amazonian shamanism, where they are derived from other plants. The harmala alkaloid harmine which was once known as Telepathine and Banisterine is a naturally occurring beta-carboline

Beta-carboline

β-Carboline is an organic amine that is the prototype of a class of compounds known as β-carbolines.-Pharmacology:...

 alkaloid

Alkaloid

Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...

 that is structurally related to harmaline

Harmaline

Harmaline is a fluorescent psychoactive indole alkaloid from the group of harmala alkaloids and beta-carbolines. It is the reduced hydrogenated form of harmine.-Occurrence in nature:...

, and also found in the vine Banisteriopsis caapi

Banisteriopsis caapi

Banisteriopsis caapi, also known as Ayahuasca, Caapi or Yage, is a South American jungle vine of the family Malpighiaceae. It is used to prepare Ayahuasca, a decoction that has a long history of entheogenic uses as a medicine and "plant teacher" among the indigenous peoples of the Amazon Rainforest...

.