[{"from": "human", "value": "Describe this molecule. [C][C][Branch1][C][C][Branch2][Branch1][Ring1][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][C][Branch2][Ring2][Ring2][C][C][C][N][C][C][C][Branch1][Branch1][C][C][Ring1][=Branch1][C][Branch1][=Branch2][C][=C][C][=C][C][=C][Ring1][=Branch1][Branch1][=Branch2][C][=C][C][=C][C][=C][Ring1][=Branch1][O][O][C][=Branch1][C][=O][O].[Cl]"}, {"from": "gpt", "value": "The molecule is the hydrochloride salt form of fexofenadine, a carboxylated metabolic derivative of terfenadine and second generation, long-lasting selective histamine H1 receptor antagonist, with antihistaminic activity. Upon administration, fexofenadine competitively binds of peripheral H1-receptors in the gastrointestinal (GI) tract, blood vessels, and bronchial smooth muscle. This prevents binding of histamine to peripheral H1-receptors and prevents their activation. This prevents a histamine-mediated allergic reaction. Fexofenadine does not cross the blood-brain-barrier (BBB)."}]