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. The dye is used as a food coloring and in cosmetics; within the European E number schedule, it is numbered E103. It is used as a red-brown food additive in regions such as Australia. Alkannin is deep red in an acid and blue in an alkaline environment. The chemical structure as a naphthoquinone derivative was first determined by Hans Brockmann in 1936. The (R)-enantiomer of alkannin is known as shikonin, and the racemic mixture of the two is kn
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. The dye is used as a food coloring and in cosmetics; within the European E number schedule, it is numbered E103. It is used as a red-brown food additive in regions such as Australia. Alkannin is deep red in an acid and blue in an alkaline environment. The chemical structure as a naphthoquinone derivative was first determined by Hans Brockmann in 1936. The (R)-enantiomer of alkannin is known as shikonin, and the racemic mixture of the two is known as shikalkin.
== Biosynthesis == The enzyme 4-hydroxybenzoate geranyltransferase utilizes geranyl diphosphate and 4-hydroxybenzoic acid to produce 3-geranyl-4-hydroxybenzoic acid and diphosphate. These compounds are then used to form alkannin.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).