[{"from": "human", "value": "What can you tell me about this molecule? [C][Branch1][=Branch2][C][Branch1][C][F][Branch1][C][F][F][Branch1][=Branch2][C][Branch1][C][F][Branch1][C][F][F][Branch1][C][F][F]"}, {"from": "gpt", "value": "The molecule is a Contrast Agent for Ultrasound Imaging. The mechanism of action of perflutren is as an Ultrasound Contrast Activity."}]