METHOD FOR MODIFICATION IN MICHAEL ADDITION REACTION FOR THE EFFCIENT COUPLING OF LAWSONIA ON ELECTRON POOR OLEFINS SUCH AS NEGTEAVILLY CHARGED HAIR, SKIN AND OTHER ANIONIC CHARGED CELLS
The phytochemistry of henna was largely studied and revealed interesting information. Already in 1920 the dye principle was known. Lawsone (C10H6O3) the colouring matter contained in henna leaves, is fixed well by wool, silk and tenaciously by the skin [3]. In 1973, four fractions with antibacterial activity were isolated by thinlayer chromatography of the ethanol extract of Lawsone inermis leaves. 3 of which were identified as gallic acid [149-91-7], lawsone (2-hydroxy- l,4-naphthoquinone)(I) [83-72-7], and 1,4- naphthoquinone [130-15-. Then in 1976, a coumarin, lacoumarin, was isolated from L. inarmis. It was then the turn of xanthones two xanthones isolated from L. inermis were characterized as 1,3- dihydroxy-6,7-dimetlioxyxanthone and 1 -hydroxy-3,6-diacetoxy-7- methoxyxanthone and named laxanthone I and II, respectively.
