[{"from": "human", "value": "Could you provide a description of this molecule? [C][C][N][C][=Branch1][Branch1][=N][C][Ring1][=Branch1][N][C][C][C][N][C][C@H1][C][C][C][=C][C][=C][C][=C][Ring1][=Branch1][O][Ring1][#Branch2]"}, {"from": "gpt", "value": "The molecule is a benzopyran lacking the indole ring of the triptans with vasoconstrictor activity. Alnitidan selectively binds to and activates serotonin 5-HT 1B and 1D receptors in the central nervous system (CNS), thereby causing extracerebral, intracranial blood vessel constriction. This may lead to pain relief from vascular headaches. Furthermore, alniditan may potentially reduce plasma protein extravasation, which may be another mechanism by which this agent relieves vascular headaches."}]