Purine
= Purine
<Purine> is the fused six- and five-membered <nitrogen> heterocyclic framework underlying <adenine> and <hypoxanthine>. Its numbered ring nitrogens distinguish <protonation> and hydrogen-bonding sites.
= Purine
<Purine> is the fused six- and five-membered <nitrogen> heterocyclic framework underlying <adenine> and <hypoxanthine>. Its numbered ring nitrogens distinguish <protonation> and hydrogen-bonding sites.