[{"from": "human", "value": "Use the given information to create a molecule that fulfills the desired purpose. The molecule is an indole derivative with antiemetic activity.  As a selective serotonin receptor antagonist, tropisetron competitively blocks the action of serotonin at 5HT3 receptors, resulting in suppression of chemotherapy-and radiotherapy-induced nausea and vomiting. (NCI04)"}, {"from": "gpt", "value": "[C][N][C@@H1][C][C][C@H1][Ring1][Branch1][C][C][Branch1][Ring2][C][Ring1][#Branch1][O][C][=Branch1][C][=O][C][=C][N][C][=C][C][=C][C][=C][Ring1][=Branch1][Ring1][=Branch2]"}]