Glaucine (also known as 1,2,9,10-tetramethoxyaporphine, bromcholitin, glauvent, tusidil, and tussiglaucin) is an aporphine alkaloid found in several different plant species in the family Papaveraceae, such as Glaucium flavum, Glaucium oxylobum, and Corydalis yanhusuo, and in other plants such as Croton lechleri in the family Euphorbiaceae.
It has bronchodilator, neuroleptic and antiinflammatory effects, acting as a PDE4 inhibitor and calcium channel blocker, and is used medically as an antitussive in some countries. TLRs plays role in its anti inflammatory effects. Glaucine may produce side effects such as sedation, fatigue, and a hallucinogenic effect characterised by colourful visual images, and has been detected as a novel psychoactive drug. In a 2019 publication, the isomer (R)-glaucine is reported to be a positive allosteric modulator of the 5-HT2A receptor, which is also associated with the hallucinogenic effects of substances such as psilocybin and mescaline.