الفهرس 
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Abstract
The work described in this thesis has been undertaken with the objective of searching for naturally occurring substances of potentially biological activities in Egyptian flora especially some plants to family Cyperaceae. Through this investigation a useful information were derived from the application of the modern technique of chromatography (column, thin-layer, paper chromatography) and spectral measurements such as UV, IR, MS, 1H-NMR, 13C-NMR, APT, DEPT, 1H-1HCOSY, HMQC and HMBC. The introductory part of this thesis comprises detailed accounts of the previously isolated natural products and their structural types encountered in nature, in addition to a brief account of the botanical aspect, medicinal and economic uses of the investigated family plants. The results and discussion as apart of the thesis describe the original work carried out and is summarized under the following titles: CHAPTER 1 Preliminary phytochemical screening of some Cyperaceae plants This chapter deals with phytochemical screening of selected plants for their alkaloids, flavonoids, sterols and/or triterpenoids, cardiac glycosides, tannins, saponins and coumarins. Twenty two accessions, representing the family Cyperaceae and four genera were phytochemically screened.Test for alkaloids were based on combined response to silicotungestic acidand Valser’s reagents. Flavonoids were detected by application of Willstatter’s reaction. Detection of unsaturated sterols and/or triterpenoid alcohols wereconducted by Liebermann-Burchardt test and Salkowski test. Cardiac glycosideswere tested by their response to kedd’s reagent with confirmation by Keller-Kilianiand Liebermann-Burchardt reagents. Tannins were confirmed by the addition offerric chloride reagent and saponins were confirmed by Wall’s test (froth test). Alkaloids were detected in one plant sample. Flavonoids in twenty two samples. Sterols and/or triterpenoid alcohols in twenty two samples. Tannins were
detected in twenty two samples and cardiac glycosides were detected in 15 samples. Saponins were detected in 17 samples. Concerning the coumarin content, the author carried out a method for the isolation of coumarin mixture and ultraviolet assay. The method for the screening of small samples of plant material was developed to enable the detection, evaluation and identification of coumarin constituents. The method depends on the initial extraction of coumarin concentrates from plant tissues by a selective procedure. Preparative layer chromatography was the final step of purification to effect further selection. Spectrophotometric assay of the coumarin content was performed in UV spectrum in the range 200-400 nm. Measurements in this range gave an approximate indication of the coumarin contents by comparison with standard curves and the results expressed as(+),(++) and(+++) for low, medium and high content, respectively.