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|Section2= |Section3= |Section8= }} Lawsone (2-hydroxy-1,4-naphthoquinone), also known as hennotannic acid, is a red-orange dye present in the leaves of the henna plant (''Lawsonia inermis'') as well as in the flower of water hyacinth (''Eichhornia crassipes''). Humans have used henna extracts containing lawsone as hair and skin dyes for more than 5000 years. Lawsone reacts chemically with the protein known as keratin in skin and hair, in a process known as Michael addition, 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 sunless tanning and sunscreens. Chemically, lawsone is similar to juglone, which is found in walnuts. Lawone isolation from ''Lawsonia Inermis'' can be difficult due to its easily biodegradeable nature. Isolation involves four steps: 1) extraction with an extraction solution, usually NaOH, 2) column filtration using a macroporous adsorption resin, 3) a rinse with ethanol to remove impurities, and finally 4) freeze- the product to isolate the lawsone powder, usually a yellow colored dust. 〔Shuang, S.; Lei, Q.; Ting, Y.; Qifu, Y. Method for preparing lawsone from lawsonia inermis China Patent CN 103848732 A, June 11, 2014.〕 Lawsone is hypothesized to undergo a reaction similar to Strecker synthesis in reactions with amino acids. 〔Jelly, R.; Lewis, S. W.; Lennard, C.; Lim, K. F.; Almog, J. Lawsone: a novel reagent for the detection of latent fingermarks on paper surfaces. Chem.Commun. 2008, 3513-3515〕 Recent research has been conducted on lawsone's potential applications in the forensic science field. Since lawsone shows many similarities with ninhydrin, the current reagent for latent fingerprint development, studies have been conducted to see if lawsone can be used in this field. As of now the research is inconclusive, but optimistic. Lawsone non-specifically targets primary amino acids, and displays photoluminescence with forensic light sources.〔 == Related compounds == The naphthoquinones lawsone methyl ether and methylene-3,3'-bilawsone are some of the active compounds in ''Impatiens balsamina'' leaves. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「lawsone」の詳細全文を読む スポンサード リンク
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