Lawsone
From Wikipedia, the free encyclopedia
Lawsone (2-Hydroxy-1,4-Naphthoquinone), or hennotannic acid, is a red-orange pigment present in the leaves of the henna plant as well as impatiens balsamica. Humans have used henna extracts containing lawsone as hair and skin pigments for more than 5000 years. In an acidic solution, lawsone can react via michael addition with the protein keratin in skin and hair, resulting in a strong permanent stain that lasts until the skin or hair is shed. Lawsone strongly absorbs UV light, and aqueous extracts can be effective, self-tanning sunscreens. Chemically, lawsone is similar to juglone, which is found in walnuts. Lawsone is known as Natural Orange 6 or C.I. 75480.
[edit] References
- The Merck Index, 12th Edition. 5406
- A. C. Dweek, Natural ingredients for colouring and styling. Int. J. Cosmetic Sci. 2002 24, 287-302.
[edit] External links
- Lawsone on the Henna Page[1]
