This image illustrates the chemical structure of a purine molecule, highlighting the numbering of the carbon and nitrogen atoms. The purine structure consists of a pyrimidine ring (positions 1 to 6) ...

Chemotherapy drugs can kill cancer cells by halting DNA replication, but a glucose-depleted environment can help cancer cells ...

This diagram depicts the chemical structure of pyrimidine, a six-membered aromatic ring with two nitrogen atoms at positions 1 and 3 (highlighted in blue). The remaining positions are occupied by ...