الفهرس 
Introduction
Stemphylium botryosumOnly 14 pages are availabe for public view
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Abstract
Plant endophytic fungi produce natural products with a large diversity of chemical structures which might prove to be suitable for specific medicinal or agrochemical applications. Most of these secondary metabolites show biological activities in pharmaceutically relevant bioassay systems and thus represent potential lead structures which could be optimized to yield effective therapeutic and bioactive agents. The aim of this work was the isolation of secondary metabolites from endophytic fungi, followed by structure elucidation and examination of their pharmacological potential. Four endophytic fungal strains (corynespora cassiicola, stemphylium botryosum, stemphylium solani and embellisia eureka) were selected as biological sources. The fungi were grown in liquid wickerham medium as well as in solid rice medium for a period of three to four weeks. The extracts obtained were then subjected to different chromatographic separation techniques in order to isolate the secondary metabolites. Structure elucidation of secondary metabolites was performed using state-of-the art analytical techniques, including mass spectrometry (MS) and nuclear magnetic resonance (NMR) experiments. In addition in the case of selected optically active natural products, chiral derivatisation methods were applied in order to determine their absolute configuration. Finally the isolated compounds were subjected to various bioassays to examine their cytotoxic activities. 1-corynespora cassiicola Corynespora cassiicola was isolated from the mangrove plant laguncularia racemose (combretaceace). Eighteen compounds were isolated from different cultures of corynespora cassiicola. These compounds belong to naphthaquinoes ,octalactones, decalactones and depsidones. Fourteen compounds are new natural products.