[{"from": "human", "value": "Could you provide a description of this molecule? [C][N][C][=N][C][=Branch2][Ring1][C][=C][Ring1][Branch1][S][C][=N][C][=N][C][=C][Ring1][=Branch1][N][C][=N][Ring1][Branch1][N+1][=Branch1][C][=O][O-1]"}, {"from": "gpt", "value": "The molecule is a prodrug of 6-mercaptopurine, first synthesized in 1956 by Gertrude Elion, William Lange, and George Hitchings in an attempt to produce a derivative of 6-mercaptopurine with a better therapeutic index. Azathioprine is used to treat inflammatory conditions like rheumatoid arthritis and as an immunosuppressant in the prevention of renal transplant rejection.  Azathiprine was granted FDA approval on 20 March 1968."}]