Alkannin | |
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5,8-Dihydroxy-2-[(1S)-1-hydroxy-4-methylpent-3-en-1-yl]naphthalene-1,4-dione |
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Other names
C.I. Natural Red 20; Alkanet extract |
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Identifiers | |
CAS number | 517-88-4 |
PubChem | 72521 |
ChemSpider | 65430 |
KEGG | C10292 |
ChEMBL | CHEMBL28457 |
Jmol-3D images | Image 1 |
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Properties[1] | |
Molecular formula | C16H16O5 |
Molar mass | 288.29 g/mol |
Appearance | Red-brown crystalline prisms |
Melting point |
149 °C, 422 K, 300 °F |
Solubility in water | Sparingly soluble |
Hazards | |
LD50 | 3.0 g/kg (mice) |
(verify) (what is: / ?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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Infobox references |
Alkannin is a natural dye that is obtained from the extracts of plants from the borage family Alkanna tinctoria that are found in the south of France. The dye is used as a food coloring and in cosmetics. It is used as a red-brown food additive in regions such as Australia,[2] and is designated in Europe as the E number E103, but is no longer approved for use..[3]
The chemical structure as a naphthoquinone derivative was first determined by Brockmann in 1936.[4] Alkannin has a deep red color in a greasy or oily environment and a violet color in an alkaline environment. Biosynthetically, alkannin is produced in plants from the intermediates 4-hydroxybenzoic acid and geranyl pyrophosphate.[5]
Alkannin is an antioxidant[6] and has an antimicrobial effect against Staphylococcus aureus and Staphylococcus epidermidis. It is also known to have wound healing, antitumor, and antithrombotic properties.[5]