The purine structure consists of a pyrimidine ring (positions 1 to 6) fused to an imidazole ring (positions 7 to 9). Adenine and guanine, the two most common purines in DNA and RNA, share this core ...

Elion was assigned a subgroup called purines. (Two of the four bases in DNA are purines -- adenine and guanine.) Hitchings reasoned that since bacteria, tumors, and certain parasites need large ...

the purine bases adenine and guanine, which are building blocks of DNA. They soon discovered, from observing the role of purines in nucleic acid metabolism, that bacterial cells require certain ...

The pyrimidines, thymine (DNA), uracil (RNA), and cytosine are shown on top while the purines, adenine and guanine, are shown at the bottom. (Image: adapted from Wikimedia Commons, public domain) The ...