A new series of coumarin derivatives having monoamine oxidase inhibitory activity from Monascus anka.

Monankarins A-F (1-6), a new series of pigments having conjugated pyrano-coumarin skeleton have been isolated from Monascus anka. Their structures have been elucidated by spectroscopic means and chemical modification. Monankarins A-D exhibited monoamine oxidase (MAO) inhibitory activity, while the activity was not observed in monankarins E and F or some other simple coumarins. Monankarin C (3) showed stronger inhibition of MAO-B than MAO-A in mice brain. However, the specificity was not found in mice liver MAO.