Compounds based on pyrazino[2,3-d]pyrimidine which is a pyrimidine fused to a pyrazine, containing four NITROGEN atoms.

Pteridines with a 4-keto OXYGEN.

Synonyms: 0, Pteridinone, Pteridine, Pyrazinopyrimidines, Pyrazinopyrimidine, Pteridines, Pteridinones