Definition of guanine in English:



  • A compound that occurs in guano and fish scales, and is one of the four constituent bases of nucleic acids. A purine derivative, it is paired with cytosine in double-stranded DNA.

    • ‘There are four DNA bases: adenine, cytosine, guanine, and thymine (A, C, G, and T).’
    • ‘The derivatives of purine are called adenine and guanine, and the derivatives of pyrimidine are called thymine, cytosine and uracil.’
    • ‘The film's name comes from the initials of the four DNA bases of our genetic code: guanine, adenine, cytosine and thymine.’
    • ‘The purines adenine and guanine are constituents of DNA.’
    • ‘The four become cytosine, guanine, adenine, and thymine, and the quantum forces that maintained the rest of universe sit on the sidelines while life take center stage.’


Mid 19th century: from guano + -ine.