[{"from": "human", "value": "Provide a description of this molecule. [C][C][=Branch1][C][=O][O][C][C][Branch2][Ring1][Ring1][C][C][N][C][=N][C][=C][N][=C][Branch1][#Branch1][N][=C][Ring1][=Branch1][Ring1][=Branch2][N][C][O][C][=Branch1][C][=O][C]"}, {"from": "gpt", "value": "The molecule is a guanine analogue used to treat herpes virus infections. It is most commonly used to treat herpes zoster (shingles). Famciclovir is a prodrug of penciclovir with higher oral bioavailability."}]