/puy rim"i deen', pi-, pir"euh mi deen', -din/, n. Biochem.1. a heterocyclic compound, C4H4N2, that is the basis of several important biochemical substances.2. one of several pyrimidine derivatives, esp. the bases cytosine, thymine, and uracil, which are fundamental constituents of nucleic acids.[1880-85; b. PYRIDINE and IMIDE]
* * *Any of a class of heterocyclic compounds with a ring structure of four carbon and two nitrogen atoms.The simplest member, pyrimidine itself (C4H4N2), is not common, but derivatives with the structure are. Examples include thiamine (vitamin B1), several sulfa drugs, barbiturates, and three of the bases in nucleic acids (cytosine, thymine, and uracil).
* * *any of a class of organic compounds of the heterocyclic series characterized by a ring structure composed of four carbon atoms and two nitrogen atoms. The simplest member of the family is pyrimidine itself, with molecular formula C4H4N2.Several pyrimidine compounds were isolated between 1837 and 1864, but their structures were not recognized until 1868. Some well-known pyrimidine compounds include cytosine, thymine, and uracil, present in nucleic acids; thiamine (vitamin B1); and sulfadiazine, sulfamerazine, and sulfamethazine, drugs used in therapy of bacterial and viral diseases.
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