تصفح Chemistry & Earth Sciences حسب المؤلف "Rizk, A. M."
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The amino acid composition of some Common marine algae from Qatar (Arabian Gulf)
Heiba, H. I. [حلمي اسماعيل هيبة]; Al-Nagdy, S. A.; Rizk, A. M.; Durgham, M. M. ( Qatar University , 1993 , Article)The most dominant twenty algal species representing the main three groups of benthic macroalgae, Chlorophyceae, Phaeophyceae and Rhodophyceae were collected from the coastal zones of the Qatar peninsula. The algae were ... -
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. -
Constituents Of Green Beans Phaseolus Vulgaris (Lipids And Flavonoids)
Rizk, A.M.; Ismail, S.I.; Azzam, S.A.; Wood, G. ( Qatar University , 1992 , Article)Chemical study of the lipid fraction resulted in the isolation and identification of a hydrocarbon fraction (n-Czg -0-033); an aliphatic alcohol fraction (C^, Czp, €30) and a sterol fraction (stigmasterol and sitosterol). ... -
Constituents of plant growing in Qatar. II. Investigation of Euphorbia granulata
Rizk, A. M.; Al-Nagdy, S. A.; El-Missiry, M. M. (1982 , Article)N/A. -
Constituents of plants growing in Qatar
Rizk, A. M.; Heiba, H. I.; Ma'ayergi, H. A.; Batanouny, K. H. ( Elsevier , 1986 , Article)N/A. -
Constituents of plants growing in Qatar - Part XIX. Flavonoids of Glossonema edule N. E. Br.
Rizk, A. M.; Hammouda, F. M.; Ismail, S. I.; Hassan, N. M.; El-Missiry, M. M.; Ahmad, F. A.... more authors ... less authors ( Springer Nature , 1990 , Article)The study of the flavonoids of the unripe fruits of Glossonema edule, resulted in the isolation and identification of apigenin 6,8-di-C-glucoside (violanthin) and luteolin 7-O-glucoside. © 1990 Kluwer Academic Publishers. -
Constituents of plants growing in Qatar III - Nutritive constituents of Garawah (Glossonema edule)
Rizk, A. M.; Hammouda, F. M.; Hussein, L. ( Junk Publishers , 1983 , Article)Both the pericarp and the unripe seeds of the unripe fruits of Glossonema edule were separately analysed. The crude protein content of the unripe seeds is double that of the pericarp. Investigation of the amino acids of ... -
Constituents of plants growing in Qatar IX. The antispasmodic components of cymbopogon parkeri stapf. Parkeri stapf
Rizk, A. M.; Rimpler, H.; Ghaleb, H.; Heiba, H. I. ( Taylor & Francis , 1986 , Article)Investigation of the lipid fraction of Cymbopogon parkeri revealed the presence of several active constituents, one of which possesses an antispasmodic activity and was identified as cryptomeridiol. Study of the other ... -
Constituents of plants growing in Qatar part XV. Chemical investigation and pharmacotoxicity of pyrrolizidine alkaloids of moltikiopsis ciliata
Rizk, A. M.; Hammouda, F. M.; Ismail, S. I.; Hassan, N. M.; Hosseiny, H. A.; Roeder, E.; Wiedenfeld, H.; Ghaleb, H. A.; Madkour, M. K.... more authors ... less authors ( Taylor & Francis , 1988 , Article)Chemical study of the alkaloidal constituents of Moltikiopsis ciliata resulted in the isolation and identification of heliotrine and echinatine, in addition to other minor alkaloids. Pharmacological experiments revealed: ... -
Constituents of plants growing in Qatar VII an examination of certain plants for anti-inflammatory activity
Rizk, A. M.; Williamson, E. M.; Evans, F. J. ( Taylor & Francis , 1985 , Article)Six desert plants native to the State of Qatar were successively extracted with hexane, chloroform and ethanol. These extracts were examined for their ability to inhibit aggregation of rabbit blood platelets induced by ... -
Constituents of plants growing in Qatar XVII anti-inflammatory and cytotoxic activities of extracts of thirty indigenous species
Rizk, A. M.; Heiba, H. I. ( Taylor & Francis , 1990 , Article)Thirty plants, indigenous to Qatar, were extracted separately with hexane, chloroform and ethanol. The dried extracts were examined for potential anti-inflammatory activities both in vitro by their ability to inhibit ... -
Constituents of Plants Growing in Qatar, Part XXX: A New Iridoid from Cistanche Phelypaea (L) COUT
Deyama, T.; Yahikozawa, K.; Al-Easa, H.S.; Rizk, A.M. (1995 , Article)New iridoid named phelypaeside (1) was isolated from the dried aerial parts of Cistanche phelypae (Orobanchaceae) growing in Qatar -
Constituents of Plants Growing in Qatar, Part XXXI: Lipid constituents of seventeen range plants growing in Qatar
Al-Easa, H.S.; Rizk, A.M.; Heiba, H.I. (2002 , Article)A preliminary study on the nutritive values of 17 Qatari range plants -
Constituents of plants growing in Qatar: part xxviii. Constituents Of cistanche phelypaea
Deyama, T.; Yahikozawa, K.; Al-Easa, H.S.; Rizk, A.M. ( Qatar University , 1995 , Article)Ten compounds were isolated from the methanolic extract of the aerial parts of Cistanche phelypaea (Orobanchaceae) and identified as echinacoside (1), tubuloside A (2), tubuloside E (3), acteoside (4), 2'-acetylacteoside ... -
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. -
Major sterol composition of some algae from Qatar
Al Easa, Hala S.; Kornprobst, Jean-Michel; Rizk, A.M. ( Elsevier Science Ltd. , 1995 , Article)Thirteen macroscopic algae belonging to the three main divisions Chlorophyceae, Rhodophyceae and Phaeophyceae from the coast of Qatar (Arabian Gulf) were investigated for their sterol composition by using GC-MS coupling ... -
Occurrence of pyrrolizidine alkaloids in Heliotropium bacciferum Forssk. Constituents of plants growing in Qatar XIII
Rizk, A. M.; Hammouda, F. M.; Roder, E.; Wiedenfeld, H.; Ismail, S. I.; Hassan, N. M.; Hosseiny, H. A.... more authors ... less authors (1988 , Article)N/A. -
Poisonous plants contaminating edible ones and toxic substances in plant foods IV. Phytochemistry and toxicity of lolium temulentum
Hammouda, F. M.; Rizk, A. M.; El-Missiry, M. M.; Ghaleb, H. A.; Madkour, M. K.; Pohland, A. E.; Wood, G.... more authors ... less authors ( Taylor & Francis , 2008 , Article)Different procedures were carried out for the preparation and separation of the total alkaloids of Lolium temulentum. Loline has been identified as the major pyrrolizidine alkaloid of the seeds. The toxicity of the alcoholic ...