[{"from": "human", "value": "Provide a description of this molecule. [C][=C][C][=Branch1][C][=O][O][C][=C][C][=C][Branch1][=Branch1][C][=C][O][Ring1][Branch1][C][=C][Ring1][=Branch2][Ring1][=C]"}, {"from": "gpt", "value": "The molecule is a furocoumarin that intercalates with DNA, inhibiting DNA synthesis and cell division. Psoralen is used in Photochemotherapy with high-intensity long-wavelength UVA irradiation. Psoralens are tricyclic furocumarins and have a strong tendency to intercalate with DNA base pairs. Irradiation of nucleic acids in the presence of psoralen with long wave UV (~360 nm) results in the 2+2 cyclo- addition of either of its two photoreactive sites with 5,6-carbon bonds of pyrimidines resulting in crosslinking double-stranded nucleic acids."}]