One of the early purine analogs showing antineoplastic activity. It functions as an antimetabolite and is easily incorporated into ribonucleic acids.

Synonyms: Q150359I72, 8-Azaguanine, 7H-1,2,3-Triazolo(4,5-d)pyrimidin-7-one, 5-amino-1,4-dihydro-, Azaguanine, Guanazolo, 8 Azaguanine