Pteridine
Template:Short description Template:Chembox
A pteridine is a bicyclic heterocyclic system with two nitrogen atoms at positions 1 and 4 in ring A, and two nitrogen atoms at positions 1 and 3 in ring B. Pteridines constitute a large group of heterocyclic compounds containing a wide variety of substituents on this parent structure. Pterins and flavins are classes of substituted pteridines that have diverse biological roles.<ref>Template:Cite journal</ref>
File:Pteridinsynth2.svg
Synthesis of pteridine from 4,5-diaminopyrimidine and glyoxal