Английская Википедия:Alkannin
Шаблон:Chembox 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 colouring and in cosmetics. It is used as a red-brown food additive in regions such as Australia.[1] Alkannin is deep red in an acid and blue in an alkaline environment.[2] The chemical structure as a naphthoquinone derivative was first determined by Brockmann in 1936.[3] The R-enantiomer of alkannin is known as shikonin, and the racemic mixture of the two is known as shikalkin.[4][5]
Biosynthesis
The enzyme 4-hydroxybenzoate geranyltransferase utilises geranyl diphosphate and 4-hydroxybenzoate to produce 3-geranyl-4-hydroxybenzoate and diphosphate. These compounds are then used to form alkannin.[5]
Research
Because the root bark (cork layers) of this plant contains large amounts of red naphthoquinone pigments, the roots of these plants are red-purple. If shikonin is extracted from fresh tissues, it gradually darkens over several days, finally forming black precipitates, which are thought to be polymers.[6]
References
External links
- ↑ Additives Шаблон:Webarchive, Food Standards Australia New Zealand
- ↑ "Alkanet" in Dispensatory of the United States of America, year 1918, edited by Joseph P. Remington and Horatio C. Wood.
- ↑ Шаблон:Cite journal
- ↑ Шаблон:Cite book
- ↑ 5,0 5,1 Шаблон:Cite journal
- ↑ Kazufumi Y. (2017). Lithospermum erythrorhizon cell cultures: Present and future aspects. Plant Biotechnology 34: 131–142.
- Английская Википедия
- Food colorings
- 1,4-Naphthoquinones
- Terpeno-phenolic compounds
- Articles containing video clips
- Hydroxynaphthoquinones
- Secondary alcohols
- 3-Hydroxypropenals within hydroxyquinones
- Alkene derivatives
- Страницы, где используется шаблон "Навигационная таблица/Телепорт"
- Страницы с телепортом
- Википедия
- Статья из Википедии
- Статья из Английской Википедии