Definition of pyrimidine in US English:



  • 1A colorless crystalline compound with basic properties.

    A heteroaromatic compound; chemical formula: C₄H₄N₂

    • ‘The URA3 gene is essential for yeast pyrimidine biosynthesis.’
    • ‘The transcription of the operon is coordinately repressed in the presence of excess pyrimidine nucleotides.’
    • ‘Our analyses also suggest that the utilization of products of de novo pyrimidine biosynthesis may differ between different cell types.’
    • ‘Second, there is no branch in the pyrimidine synthesis pathway.’
    • ‘The purine and pyrimidine bases in cells are linked to carbohydrate and in this form are termed, nucleosides.’
    1. 1.1 A substituted derivative of pyrimidine, especially the bases thymine and cytosine present in DNA.
      • ‘Some introns also have a sequence rich in pyrimidines that adds up to 10 additional bases at the 3’ end.’
      • ‘Both of these products involve dimerization of adjacent pyrimidines on the same DNA strand.’
      • ‘Purines and pyrimidines are considered as complex molecules themselves because they are never synthesized as such in vivo.’
      • ‘Both purine and pyrimidine bases present similar PI yields at 266 nm.’


Late 19th century: from German Pyrimidin, from pyridine, with the insertion of -im- from imide.