Phytochemical Investigation of Holarrhena Floribunda( G.DON) Dur.et Schinz for Steroidal Alkaloids.

Okunubi, Oluwatoyin Abosede (1985)

Thesis

Holarrhena belongs to the family Apocynaceae, most of the members of which are physiologically active because of their alkaloid or glycoside contents. Conessine, one of the major alkaloids of Holarrhena species is already in clinical use in the treatment of dysentery. A review of the literature on the genus Holarrhena is presented. Quantitative estimation of the total alkaloids calculated as conessine in the different parts of H. floribunda (G. Don) Dur et Schinz in different seasons was determined. The root bark had the highest alkaloidal content followed by the stem bark, fruits, leaves and stem wood. The alkaloid content in the leaves was higher in the rainy season than in the dry season while the reverse was observed in the stem and root barks. Phytochemical investigation of the leaves resulted in the isolation of Triacanthine, compounds HFL-1 and NFL-2 while conessine, isoconessimine and compound HFB-3 were isolated from the stem bark. The structures of these compounds were determined from their spectral data:- U.V., I.R., 1H NMR, 13c NMR and M. S. Microscopical investigations were carried out on the leaves, young stem, root and on the powdered stem and root barks of the plant. The results were compared with those reported from H. antid dysenterica, the Indian variety.

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