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 anthraquinone is also included.
In the present work, various parts of Morinda citrifolia (leaves, stem and fruits) were extracted with methanol 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. Twenty two constituents were ultimately obtained and characterized through spectral studies including nine from fruits (1 to 9), eight from stem (10 to 17) and five (18 to 22) from leaves. Out of these eight compounds are new which have been named as morinaphthalenone (3), morindafurone (8), morinaphthalene (9), morindicone (12), morinthone (13), morindicinone (14), morindicininone (15) and 5-benzofuran carboxylic acid -6-formyl methyl ester (20). The remaining fourteen compounds are known constituents which include thirteen hitherto unreported compounds from this plant namely 1, 3-dimethoxyanthraquinone (1), hydroquinone (4), scopoletin (5), 1,8-dihydroxy-6-methoxy-3- methyl-9-anthrone (6), 2,4-dimethoxy-9-anthrone (7), 1-hydroxy-2-methylanthraquinone (10), 2-hydroxymethylanthraquinone (11), 2-hydroxyanthraquinone (16), 2-methoxyanthraquinone (17), stearic acid (18), palmitic acid (19), 4-(3' (R)-hydroxybutyl)-3,5,5'-trimethyl-cyclohex-2-en-l-one (21) and 4-hydroxy-4-[ 1 'E,3 'R)-3' -hydroxy-l 'butenyl]-3,5,5' -trimethyl-cyclohex-2-en-l-one (22) whereas one is earlier reported compound 1.2-dihydroxyanthraquinone (2).
The structures of the new compounds have been elucidated through sophisticated modern 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. All the extracts, their main fractions and some pure compounds were subjected to various bioassays, such as anti -HIV, anticancer, anti - leishmaniasis, spasmolytic and spasmogenic, antioxidant, pesticidal and antimicrobial activity, in collaboration with biologists who have been acknowledged for their help (vide acknowledgement). It may be noted that one pure compound is under investigation for its anticancer activity at NCI. Further, the preparation from stem which was found to have potent cutaneous anti -leishmaniasis activity in clinical trails is under detailed studies regarding its toxicity and application at large scale.