Chemosystematic studies of some species of the genus potamogeton L. in Egypt

Morphological, anatomical and a phytochemical studies were conducted on four out of seven potamogeton L. species recorded in the flora of Egypt. The stem anatomy referred to the presence of three types of steles and three types of endodermis. The chemical investigation revealed the presence of eleven flavonoid compounds, the distribution of which was traced in the studied species to evaluate the interspecific affinity through this parameter It was found that the chemical data in this work justify the classification of ascherson and graebner [1907] as regards the assignment of the four studied species to their sections. A key based on a combination of the anatomical and chemical characters was suggested for species delimitation

Chemosystematic studies of five melilotus species

Flavonoid glycosides of five Melilotus species belonging to the family Fabaceace were investigated. Eight flavonoid glycosides were found. The chemosystematic relationship between the five Melilotus Species is discussed

Hydrolysable tannins and coumarin from ceratonia siliqua

A new hydrolysable tannin: 1-methyl-2,3-di-O-galloyl-alpha-[4]C[1]- glucopyranose [1] was isolated from the fruits of Ceratonia siliqua, together with six known phenolic compounds [2-7]. The structures of the isolated compounds were elucidated by chemical and spectroscopic analyses. The known compounds were 2,3,4-tri-O-galloyl-[alpha/beta-[4]C[1] -glucopyranose [2], 1,2,36-tetra-O-galloyl-beta[4]C[1]-glucopyranose [3], 1,2,6-tri-O-galloyl- beta-[4]C[1] -glucopyranose [4], gallic acid methyl ester[5], gallic acid [6] and 7,8-dihydroxycoumarin [7]. The alcoholic extract [70%] and gallic acid [isolated from the same extract] exhibited an antioxidant activity by Paramagnetic Spin Resonance method

chemosystematics of Egyptian onopordum species [compositae]

From the leaves and stems of Onopordum alexandrinum, 11 flavonoid compounds were isolated and identified as apigenin, luteolin, chrysoeriol and their 7-galactosides and 7-glucosides together with the 7-diglucosides of apigenin and chrysoeriol