What is imidazole ring?

Some articles on imidazole ring:

Histamine - Properties
... The imidazole ring has two nitrogens ... the aliphatic amino group and whichever nitrogen atom of the imidazole ring does not already have a proton ... a pKa around 9.4) will be protonated, whereas the second nitrogen of the imidazole ring (pKa ≈ 5.8) will not be protonated ...

Famous quotes containing the word ring:

    The boxer’s ring is the enjoyment of the part of society whose animal nature alone has been developed.
    Ralph Waldo Emerson (1803–1882)