Coptisine

Coptisine is an alkaloid found in Chinese goldthread (Coptis chinensis). Famous for the bitter taste that it produces, it is used in Chinese herbal medicine along with the related compound berberine for treating digestive disorders caused by bacterial infections.

Also found in Greater Celandine and has also been detected in Opium.

Coptisine has been found to reversibly inhibit Monoamine oxidase A in mice, pointing to a potential role as a natural antidepressant. However, this may also imply a hazard for those taking other medications or with a natural functional disorder in Monoamine oxidase A.

Coptisine was found to be toxic to larval brine shrimp and a variety of human cell lines, potentially implying a therapeutic effect on cancer or alternatively a generally toxic character. The same authors illustrate a four-step process to produce Coptisine from Berberine.