[{"from": "human", "value": "Provide a brief overview of this molecule. [C][=N][C][=Branch2][Ring1][#Branch2][=N][C][=Branch1][C][=O][N][Ring1][#Branch1][C@H1][C@@H1][Branch1][=N][C@@H1][Branch1][=Branch2][C@H1][Branch1][Ring2][O][Ring1][Branch1][C][O][O][O][N]"}, {"from": "gpt", "value": "The molecule is only found in individuals that have used or taken this drug. It is a pyrimidine nucleoside analogue that inhibits DNA methyltransferase, impairing DNA methylation. It is also an antimetabolite of cytidine, incorporated primarily into RNA. Azacytidine has been used as an antineoplastic agent. Azacitidine (5-azacytidine) is a chemical analogue of the cytosine nucleoside used in DNA and RNA. Azacitidine is thought to induce antineoplastic activity via two mechanisms; inhibition of DNA methyltransferase at low doses, causing hypomethylation of DNA, and direct cytotoxicity in abnormal hematopoietic cells in the bone marrow through its incorporation into DNA and RNA at high doses, resulting in cell death. As azacitidine is a ribonucleoside, it incoporates into RNA to a larger extent than into DNA. The incorporation into RNA leads to the dissembly of polyribosomes, defective methylation and acceptor function of transfer RNA, and inhibition of the production of protein. Its incorporation into DNA leads to a covalent binding with DNA methyltransferases, which prevents DNA synthesis and subsequent cytotoxicity."}]