الفهرس 
Taxonomy of gymnosperms
Material, Apparatus and MethodologyOnly 14 pages are availabe for public view
 |  | from | 311 |  |  |
| | | from | 311 | | |
Abstract
Gymnosperms are naked seed-producing plants. They form a relatively small group of about 1000 species of mainly evergreen trees or shrubs. Gymnosperms include small group of 8 orders, 12 families, 83 genera and about 1000 species of mainly evergreen trees or shrubs. Family Zamiaceae has palm-like plants, containing 9 genera and about 200 species. Dioon is one genus related to the order cycadales. Reviewing the available literature nothing could be traced concerning three species of Dioon, namely Dioon mejiae Standl. & L.O.Williams, Dioon holmgrenii De Luca, Sabato & Vázq.Torres, and Dioon meorlae De Luca, Sabato & Vázq.Torres. So these plants were selected for the present study which included five parts: Part I: Morphological & microscopical investigations of three Dioon species leaflets cultivated in Egypt. Part II: Biological investigation for the methanolic extracts of three Dioon species leaflets, including cytotoxic, antioxidant, antibacterial and antifungal activities, and the fractions of D. mejiae and D. holmgrenii were subjected to these investigations in addition to antiviral activity of methanolic extracts of D. mejiae and D. holmgrenii due to their higher effect. Part III: Phytochemical investigation of the most biologically active species, Dioon mejiae and Dioon holmgrenii. Part IV: Phytochemical investigation of Dioon mejiae and Dioon holmgrenii active constituents. Part V: In silico molecular docking results of the isolated pure compounds, for investigating their probable antiviral effect.