|Keywords (Extracted from title, table of contents and abstract of thesis)
lawsonai alba, henna, anti-tuberculosis, triterpenoids, polyketides, flavonoids, lawsowaseem, lawsoshamim, lawsonic acid, lawsonin, lawsonicin, lawsonadeem, vomifoliol
The present thesis describes phytochemical investigations on the chemical constituents of the aerial parts of Lawsonia alba (Henna) and anti-tuberculosis activity of its three pure constituents.
The introduction of the thesis gives a review of the earlier contributions made in the chemistry and pharmacology of this tree, as well as a brief account of the present work. A brief review of biosynthesis of triterpenoids, polyketides and flavonoids is also included.
In the present work the aerial parts of Lawsonia alba were extracted with dichloromethane at room temperature and the extract after removal of the solvent, was fractionated through solvent separation, followed by various chromatographic techniques such as vacuum liquid chromatography, column chromatography, and thin and thick layer chromatography. Nineteen constituents were ultimately obtained and characterized through spectral studies including six new compounds named as lawsowaseem (1), lawsoshamim (2), lawsonic acid (7), lawsonin (11), lawsonicin (17) and lawsonadeem (19).
The remaining thirteen were known constituents which included five hitherto unreported compounds from this plant namely oleanaldehyde (8), lupanaldehyde (9), benzophenone (13), benzaldehyde (14), vomifoliol (16) and eight earlier reported compounds p-hydroxycinamic acid (3), betulinic acid (4), oleanolic acid (5), 3-methylnonacosan-l-ol (6), β-sitosterol (10), betulin (12), 2-methoxynaphthoquinone (15) and β-sitoglucoside (18).
The structures of the new compounds have been elucidated through sophisticated modem spectroscopic methods including UV, IR, MS, 1H-NMR and 13C-NMR (BB and DEPT), 2D-NMR experiments (J-Resolved, COSY -45°, NOESY, HMQC and HMBC) and chemical transformations. The known compounds have been identified through comparison of their physical and spectral data with those reported for the corresponding compounds in literature.
In view of reported anti-tuberculosis activity of the plant and the prevalence of tuberculosis in tropical countries, various pure constituents obtained in the present work were submitted for the determination of their anti-tuberculosis activity under T AACF program at U.S.A. The results obtained till now show that lawsonin and lawsonadeem caused 72% and 11 % inhibition of growth of Mycobacterium tuberculi whereas lawsonic acid does not inhibit the growth of M tuberculi. The results of other pure constituents are awaited.
The biological activity of pure compounds was determined against Mycobacterium tuberculi by the courtesy of Dr. Cecil D. Kwong of Southern Research Institute, Birmingham, Alabama, U.S.A, under TAACF program.