Stem bark (covered with gum) of Acacia tortilis (Forsk.) Hayne subsp. raddiana (Savi) Brenan, used as a remedy against asthma in Somalia, contains two new pharmacologically active compounds named quracol A and B. Quracol A is 1-(2, 4-dihydroxyphenyl)-3-(3hydroxyphenyl)-propan-2-ol. Quracol B is 1-(2, 4-dihydroxyphenyl)-3-(3, 4-dihydroxyphenyl)-propan-2-ol. The compounds have very low optical activity. No optical activity can be determined for quracol A. 1H-NMR with chiral shift reagents does not indicate quracol A to be racemic. In a CD-experiment, O12 = -807 is found for quracol B.Both substances inhibit electrically induced contractions of the isolated guinea pig ileum at concentrations in the bath of 20 sgIml. Histamineinduced contractions are also inhibited.
The yields and composition, but not the components, of the volatile oil of the Sudanese medical plant Cymbopogon proximus varied widely at different stages of development and in different habitats. The main components were piperitone (22 t o 88%), elemol (0.4 to 39%) and p-eudesmol(2 to 20%). In contrast, Cymbopogon excavatus, C. nervatus and C. commutatis yielded oils containing low ((6%) proportions of sesquiterpenes and piperitone; the main constituents were now unusual p-menthadien-01s (up to 89%j. Studies of uptake of carbon dioxide-[I4 C ] into the oil of C. proximus revealed significant incorporation of tracer into both mono-and sesqui-terpenoids in short term (ca 24 hr) periods of methabolism and indicated the suitability of the species for biosynthetic studies on elenzane and eudesmane-type sesquiterpenes. A brief discussion of the biogenesis and biological significance of these oils is appended. The genus Cy~nbopogon (fam. Gramineae) contains about 40 species mostly native to the old world tropics and constitutes an important proportion of savannah grass (JACKSON, 1893). Although (as in the closely related but larger Andropogon genus) taxonomic classification is often complicated by hybridisation and polyploidy, probably nine species are found in the Sudan (ANDREWS, 1956; WICKENS, 1968). C. proximus (A. RICH.) STAPF. is the most common of these and extracts (,,Maharaibu) are widely used in folk medicine for treatment of digestive ailments and as a flavouring. A commercial preparation is available and is claimed to show antispasmodic activity (MONEIM et al., 1969; AHMED et al., 1973) and to be a diuretic (AHMED et al., 1957) and an antihistamine (EL BORO-TOSSY and EL SAYED, 1960). We now report comprehensive analyses of the steam-volatile oils of C. proximus at different stages of development from different habitats, and compare these with the oils from Sudanese specimens of C. nervatus (HOCHST.) CHIOV., C. excavatus (HOCHST.) STAPF., and C. commutatis (STEUD.
The fine powder of the shade-dried root bark of Zizyphus spina Christi [Rhamnaceae] was exhaustively extracted with aqueous ethanol at room temperature. Fractionation, isolation and purification were carried out with column chromatography. Characterization and identification of the isolated pure components were based on their spectroscopic data and comparison with data cited in literature. As a result four new compounds, three of them are lupane-type tritepenoids and the fourth compound is sterol were identified. These compounds are lupeol, betulinaldehyde, betulin and β-sitosterol.
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