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Jordan University of Science and Technology (JUST) 2004

Isolation Characterization and Biological Evaluation of Active Components of Colchicum Tauri Siehe Ex Stefanoff Colchicaceae

Amani Salem Mohammad Ma’Ayah

Titre : Isolation Characterization and Biological Evaluation of Active Components of Colchicum Tauri Siehe Ex Stefanoff Colchicaceae

Auteur : Amani Salem Mohammad Ma’Ayah

Université de soutenance : Jordan University of Science and Technology (JUST)

Grade : Master of Science (MS) 2004

Résumé
This project involved the isolation, characterization and biological evaluation of active components of Colchicum tauri Siehe ex Stefanoff. (Colchicaceae) ; an unexplored Jordanian specie. Methanolic extraction, partition (crude alkaloids fractionation), silica gel open column, and repeated preparative TLC and HPLC chromatographic separations, directed by brine shrimp lethality test (BST), resulted in the isolation and identification of eight known and two new compounds. The known compounds were :(-)-colchicine (I), 2-demethyl-(-)-colchicine (II), 3-demethyl-(-)-colchicine (III), lumicolchicine (IV), (-)-demecolcine (V), 3-demethyl-lumicolchicine (VI), apigenin (VII) and (-)-N-methyldemecolcine (VIII), have been isolated for the first time from this specie. The new compounds isolated include : the colchicine-type alkaloid 3-demethyl-(-)-N-methyldemecolcine (IX), and the lumi-derivative type alkaloid compound (X). These eight compounds are reported for the first time from this specie and the new compounds have never been isolated before from other species. The structural elucidation of these compounds were conducted by using spectroscopic techniques principally ; NMR (1H ,13C, COSY, ROESY, HMBC, HSQC) and low resolution EI-MS. Based on the brine shrimp lethality assay (BST) results, reported as LC50 values in μg/ml (ppm) with 95% confidence intervals and analyzed by a Finney PC computer program, compounds I (2.49 ppm) and V (8.1 ppm) were the most potent. In determination of the colchicine content in this Jordanian Specie, a gradient photo-diode array high performance liquid chromatography (PDA-HPLC) method was used. Among plant parts of C. tauri leave and flowers showed the highest colchicine content of 0.036 g% (wt/wt), which is within the range of colchicine content in colchicum autumnale (0.035 –1.2 ) g% (wt/wt).

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Page publiée le 5 novembre 2016, mise à jour le 22 mars 2019