Alkannin is a natural dye that is obtained from the extracts of the plant dyer's alkanet (Alkanna tinctoria) which is found in the Mediterranean region.

[2] Alkannin is deep red in an acid and blue in an alkaline environment.

[3] The chemical structure as a naphthoquinone derivative was first determined by Hans Brockmann in 1936.

[6] Because the root bark (cork layers) of Alkanna tinctoria contains large amounts of red naphthoquinone pigments, including alkannin, the roots of these plants are red-purple.

When extracted from fresh tissues, the pigment gradually darkens over several days, finally forming black precipitates, which are thought to be polymers.