Zeinab AbdEllatif Saleh AbdEllatif2018-02-192018-02-192017http://hdl.handle.net/123456789/11002A thesis Submitted to Al- Neelain University in Fulfillment of the Requirements for the Award of the M. Sc. Degree in Biology (Plant Taxonomy)Abstract Euphorbiaceae is a family of dicotyledonous flowering plant which includes a number of species distributed all over the Sudan. It contains species used as a source of food and others are medicinal that contain some bioactive compounds and are used in local medicine. The present study constitutes two parts. The first part comprises a systematic survey of the representatives of the family Euphorbiaceae s.l. Juss. in the Red Sea State based mainly on material deposited in the local herbaria in the Sudan and Kew herbarium and the author collections from Sinkat Locality. In addition to the species reported in the Sudanese floras and relevant publications. For each species standard up-dated scientific binomial, synonyms, a brief description, locations of species in the study area, habitat and economic uses are included when available. In the second part phytochemical analysis of secondary constituents in three species from family namely: Euphorbia abyssinica Gmel., E. polycantha Boiss. and Jatropha glauca Vahl (stem, seed, latex or sap) in alcohol and water solvents were carried out using standard methods. The representatives of the family Euphorbiaceae s.l. in the Red Sea State contain 29 species included within 8 genera. According to the (APG IV) system of classification the studied taxa are presented in two families: Euphorbiaceae s.s. Marc.-Berti and Phyllanthaceae s.s. Martinov. Euphorbiaceae s.s. contains 3 subfamilies: Acalyphoideae with 3 genera including 6 species, Crotonoideae 2 genera with 4 species and Euphorbioideae one genus with15 species. Phyllanthaceae contains 3genera with 4 species. The life forms of the studied members show that most of the species are Phanerophyta (59%) including 21% succulents. Herbaceous species constitute 41% most of them are Chamaephyta; Therophyta are rare. Information on collected economic uses shows that most of the species in the study area are of medicinal importance. The preliminary phytochemical screening resulted in the presence of different levels of the tested phyto-constituents: carbohydartes, alkaloids, saturated and unsaturated III sterols, saponin, coumarins, tannins, cardenolides, flavones, flavonols, deoxy sugars and traces of cyanidin and leucoanthoyanins. Quantitative analysis of saponin in aqueous extracts of Jatropha glauca and Euphorbia polyacantha yields 20% in the seeds of the studied plants. The stem of E. polyacantha contains 20% of saponin and the sap of Jatropha glauca scores the highest level (26.3%). Aqueous extracts of the latex of Euphorbia polyacantha revealed the presence of 60% alkaloids. In view of the above the family Euphorbiaceae in Sudan needs more studies using different taxonomic approaches and detailed chemical analysis.Biology