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Constituents of plants growing in qatar V. Constituents of the volatile oil of cymbopogon parkeri

A.M., Rizk; Heiba, H.I.; Sandra, P.; Mashaly, M.; Bicchi, C. ( Elsevier , 1983 , Article)

Analysis of the volatile oil of Cymbopogon parkeri has been carried out by capillary gas chromatography-mass spectrometry. To facilitate identification, prefractionation of the oil by adsorption high-performance liquid ...

Sesquiterpene lactones from Pulicaria sicula

Zdero, C.; Bohlmann, F.; Rizk, A. M. ( Elsevier , 1988 , Article)

The aerial parts of Pulicaria sicula afforded the known xanthanolides 1-6, the guaianolides 7 and 8 as well as two new ones, the lactone 9 and the corresponding epoxide 10. Furthermore nerylisobutyrate and the thymol ...

Chemical survey of some plants Growing in Qatar

Rizk, A.M.; Heiba, H.I.; Al-Easa, H.S. (1989 , Other)

Fifty one plants growing in Qatar, belonging to thirty families, were surveyed for alkaloids, anthraquinones, coumarins, flavonoids, tannins and saponins. The medicinal uses of these plants arereported.

Synthesis and biological activity of some new 3-and 6-substituted coumarin amino acid derivatives. Part I

El-Naggar, A. M.; Ahmed, F. S. M.; El-Salam, A. M. A.; Radi, M. A.; Latif, M. S. A. ( Wiley-Blackwell , 1981 , Article)

The synthesis of 6-nitrocouarrain-3-CO-amino acids and their corresponding methyl esters (II-XVII) and some dipeptide methyl esters (XVIII-XXVI) are described. 6-(N-Tosyl- or N-phthalylaminoacyl)aminocoumarin-3-carboxylic ...

Absolute evaluation of ferrous and ferric concentration in Ca amphibole

Bahgat, A. A.; Fayek, M. K. ( WILEY-VCH Verlag , 1982 , Article)

Studies are made of M?sshauer absorption of 57Fe in a Ca-amphibole schist sample at room and liquid nitrogen temperatures. The absolute concentration and the recoilless fraction for ferrous and ferric cations are determined ...

Polarization Resistance Study on Copper Corrosion in Aqueous Potassium Hydrogen Phthalate Solution

Mouhad, M. Y.; Bekheet, A. M.; Soliman, S. A. ( WILEY-VCH Verlag , 1987 , Article)

The effect of temperature on corrosion of copper in 0.1 M aqueous solution of potassium hydrogen phthalate (KHPh) has been investigated using polarization resistance technique. it was found that that the corrosion rate in ...

Mössbauer study of ZnxNi5/3−xFe1Sb1/3O4 spinel ferrite

El Nimr, M.K.; Saleh, H.A.; Fayek, M. K. ( Springer Verlag , 1985 , Article)

The antimony substituted nickel ferrite ZnxNi5/3–xFe1Sb1/3O4 with different values ofx are prepared, checked by x-ray and studied with57Fe Mössbauer spectroscopy over a wide temperature range. Characteristic spectra of ...

Inhibitory effect of sodium nitrite on corrosion of lead in 0.1 M sodium hydroxide solution

Mourad, M.Y.; Abd El-Wahaab, S.M.; Soliman, S.A.; El-Gaber, A.S. ( Council of Scientific and Industrial Research , 1988 , Article)

The effect of NaNO2 as an inhibitor for corrosion of lead in 0.1 M NaOH solution has been investigated at different temperatures using the Tafel plot technique. The concentrations of NaNO2 employed are in the range 1-5×10-5. ...

Selective determination of thiamine (vitamin B1) in pharmaceutical preparations by direct potentiometric argentometric titration with use of the silver-silver sulphide ion-selective electrode

Hassan, Saad S.M.; Elnemma, Eman ( Elsevier , 1989 , Article)

A simple and selective argentometric titration method is described for determination of thiamine (vitamin B1), based on direct potentiometric titration in alkaline media (⩾0.5M) in which a chemical transformation takes ...

Iridoids and flavonoids of Teucrium polium herb

Rizk, A. M.; Hammouda, F. M.; Rimpler, H.; Kamel, A. ( Thieme , 1986 , Article)

The iridoid glycoside teucardoside and the flavonoids salvigenin and cirsiliol have been isolated from Teucrium polium var. pilosum and T. polium var. alba. The medicinal significance of these findings is discussed.