Pyrimidines

Nitrogen-containing organic bases including thymine, cytosine and uracil, which pair with purines in DNA and RNA and whose derivatives are important in cellular metabolism and which are essential components of nucleic acids.  They are not only found in nucleic acids, but also in amino acids, antibiotics, vitamins and even a variety of toxins.  Pyrimidines have an important role in drug development (e.g., for anti-malaria medication) and are used in the treatment of AIDS.  

See Adenine, Amino acids, Cytosine, DNA (deoxyribonucleic acid), DNA double helix, Metabolism, Nucleic acid, Nucleotide, Purines, Thymine, RNA (ribonucleic acid), Uracil