A member of the class of purines that is 6,7-dihydro-1H-purine carrying a thione group at position 6. An adenine analogue, it is used in the treatment of acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), Crohn's disease, and ulcerative colitis. ChEBI: Purine-6-thiol is a thiol that is the tautomer of mercaptopurine. It has a role as an antineoplastic agent and an antimetabolite. It is a tautomer of a mercaptopurine. It derives from a hydride of a 7H-purine.