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PHOTOCHEMICAL STUDIES OF SOME PRIMULACIOUS AND LEGUMINOUS PLANTS

Qazi, Najmus Saqib (1980) PHOTOCHEMICAL STUDIES OF SOME PRIMULACIOUS AND LEGUMINOUS PLANTS. PhD thesis, University of Karachi, Karachi.

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Abstract

The present thesis consists of part-1 and Part-II. In the part-1 the phytochemical studies on two primulacious plants namely Prinula denticulate and Androsace rotundifolia are discussed. In part-II the isolated of alkaloids from Erythrina herbacea is described. Primula denticulate was subjected to chemical investigation for the isolation of saponin and sapogenins. As a result of this work five sapogenins provisionally named as pridentigenin A,B, C, D, and E were isolated in the pure form. The structure of pridentigenin B has been elucidated through spectroscopic and chemical methods. It was characterized as 3B, 16a-dihydroxy-16-methoxy-28, 30-epoxy-olean-12-ene. Pridentigenin E, another new sapognein was shown to possess the structure of 3B 16X,28,30-tetrahydroxy-olean-12-ene,. Although this compound has been obtained previously by the borohydirde reduction of cyclamiretin D, this is the first instance of its isolation from plant source. The structure of pridentigenin B and E was confirmed by the acid hydrolysis of the former to cyclamiretin D, and the borohydride reduction of the hydrolysis product to pridentigenin E. Pridentigenin A was shown to be identical with cyclamigenin D through comparison of phys cal and spectroscopic data. This is the first example of its occurrence in primula. Pridentigenin C is spectroscopically very similar to pridentigenin B but can be clearly separated from the latter on thin layer chromatogram. It is therefore, very likely that it is the sterically less stable C-30 epimer of pridentigenin B. The structure of pridentigenin D could not be elucidated completely due to the paucity of material. However th available data suggest that it also possesses, elean-12-ene skelton with hydroxyl at C-3 and one keto as well as other hydroxyl groups in ring D and E of the molecule. The quantity of pridentigenin C was also too small for any structural work As a result of chemical investigation of Androsace rotundifolia, primulagenin A was isolated and identified as the main sapogenin Studies on the alkloidal constituents of Erythrina herbacea led to the isolation of five bases out of these four were identified as erysoterine, 11-hydroxyerysotrine, erybidine, n-Nororientaline

Item Type:Thesis (PhD)
Uncontrolled Keywords:primulacious plants, leguminous plants, prinula denticulate, androsace rotundifolia, pridentigenin b, pridentigenin e, pridentigenin a, pridentigenin c, pridentigenin d, erythrina herbacea
Subjects:Agriculture & Veterinary Sciences(a)
ID Code:1090
Deposited By:Mr. Muhammad Asif
Deposited On:20 Feb 2007
Last Modified:04 Oct 2007 21:04

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