C5H5N5 adenine 9H-purine-6-amino 6-aminopurine

C5H5N5 
adenine 
9H-purine-6-amino
6-aminopurine
Adenine Adenine-3D-vdW Organic Chemistry Guanine C5H5N5O Cytosine C4H5N3O Thymine C5H6N2O2