Chemistry: Recent submissions
Now showing items 61-80 of 85
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Antioxidant activity of prenylated flavonoids from the West African medicinal plant Dorstenia mannii
(Elsevier Science Ireland Ltd. www.elsevier.com/locate/jethpharm, 2003)The antioxidant activities of three prenylated flavonoids from Dorstenia mannii (6,8-diprenyleriodictyol, dorsmanin C and dorsmanin F) were compared to the common, non-prenylated flavonoid, quercetin. The prenylated ... -
Lanneanol: A new cytotoxic dihydroalkylcyclohexenol and phenolic compounds from Lannea nigritana (Sc. Ell.) Keay
(Elsevier Ltd. www.elsevier.com/locate/biochemsyseco, 2007)The genus Lannea belongs to the family Anacardiaceae and consists of 40 species. Lannea nigritana (Sc. Elliot) Keay is a small tree of 3e6 m of height found in the tropical rain forest (Berhaut, 1971; Letouzey, 1972). It ... -
Diterpenoids from the stem bark of Croton zambesicus
(Elsevier Science Ltd. www.elsevier.com/locate/phytochem, 2002)Three clerodane diterpenoids, crotozambefurans A, B and C were isolated from the stem bark of Croton zambesicus together with the known clerodane crotocorylifuran and two trachylobanes: 7b-acetoxytrachyloban-18-oic acid ... -
Diprenylated chalcones and other constituents from the twigs of Dorstenia barteri var. subtriangularis
(Elsevier Ltd; www.elsevier.com/locate/phytochem, 2003)The twigs of Dorstenia barteri var. subtriangularis yielded three diprenylated chalcones: ( )-3-(3,3-dimethylallyl)-50-(2-hydroxy-3- methylbut-3-enyl)-4,20,40-trihydroxychalcone, (+)-3-(3,3-dimethylallyl)-40,50-[2000-(1 ... -
Antinociceptive and anti-inflammatory effects of Dorstenia barteri (Moraceae) leaf and twig extracts in mice
(Elsevier Ltd. www.elsevier.com/locate/jethpharm, 2004)The present studywas undertaken to investigate the antinociceptive and anti-inflammatory activities of the leaf and twig extracts of Dorstenia barteri (Moraceae) in mice. Both the leaf and twig extracts of Dorstenia barteri ... -
Prenylated flavonoids and other constituents from the twigs of Dorstenia angusticornis (Moraceae)*
(Elsevier Ltd. www.elsevier.com/locate/biochemsyseco, 2005-06-18)Dorstenia (Moraceae) is a mainly tropical genus of some 170 species (Mabberley, 1987). There are 23 species in Cameroon where a decoction of the leaves is administered for the treatment of cough, headache and stomach ... -
Chalcones and other constituents of Dorstenia prorepens and Dorstenia zenkeri
(Elsevier Science Ltd. www.elsevier.com/locate/phytochem, 2002)The twigs of Dorstenia prorepens furnished the digeranylated chalcone, 5,30-(3,7-dimethyl-2,6-octadienyl)-3,4, 20,40-tetrahydroxychalcone while Dorstenia zenkeri yielded the 30,40-(3-hydroxy-2,2-dimethyldihydropyrano)-4 ... -
Prenylated chalcones, flavone and other constituents of the twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis
(Elsevier Ltd. www.elsevier.com/locate/phytochem, 2004)The twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis yielded 16 compounds. Two novel diprenylated chalcones: 3,50-di-(2-hydroxy-3-methylbut-3-enyl)-4,20,40-trihydroxychalcone, 3, 4-(2,2-dimeth ... -
Homoisoflavonoids and xanthones from the tubers of wild and in vitro regenerated Ledebouria graminifolia and cytotoxic activities of some of the homoisoflavonoids
(Elsevier Ltd. www.elsevier.com/locate/phytochem, 2002)Eleven homoisoflavonoids and two xanthones were isolated and characterized from the bulbs of Ledebouria graminifolia. Five of the homoisoflavonoids are new compounds and were identified as: 5-hydroxy-7-methoxy-3-(40-hyd ... -
Two new anthraquinones from Gladiolus psittascinus
(Elsevier Ltd. www.elsevier.com/locate/biochemsyseco, 2007)Gladiolus psittascinus HOOK, an herbaceous plant, is propagated by its bulb. This onion-looking plant occurs in rocky places in western province of Cameroon. The bulbs are used to treat asthma, gonorrhoea, diabetes and ... -
Photochromism, anomalous multi-banded fluorescence and laser properties of some amino- and tosyl-amino derivatives of oxadiazole
(Elsevier Science Ltd. www.elsevier.com/locate/saa, 2006)The multi-banded fluorescence and laser properties of 11 new amino- and tosylamino derivatives of 2,5-di(phenyl)-1,3,4-oxadiazole and oxadiazole in various solvents at 293K are reported. All the compounds investigated ... -
The first 60-O-sulfated phenylanthraquinones: isolation from Bulbine frutescens, structural elucidation, enantiomeric purity, and partial synthesis
(Elsevier Ltd.http://www.elsevier.com/wps/find/journaldescription.cws_home/942/description#description, 2005)From the roots of Bulbine frutescens, the first sulfated phenylanthraquinones were isolated, together with their known sulfate-free analogs. Their structures were elucidated by spectroscopic and chiroptical methods, by ... -
Antimicrobial activity of the methanolic extracts and compounds from Treculia africana and Treculia acuminata (Moraceae)
(Elsevier Ltd. www.elsevier.com/locate/sajb, 2007)The crude methanolic extracts from Treculia africana and Treculia acuminata, three compounds isolated from T. africana and identified as, Phyllocoumarin (1), Catechin (2) and 6, 9-dihydroxy-megastigmane-3-one (3), four ... -
Rotenoid derivatives and other constituents of the twigs of Millettia duchesnei
(Elsevier Ltd. www.elsevier.com/locate/phytochem, 2007)Three prenylated rotenoids, elliptol, 12-deoxo-12a-methoxyelliptone and 6-methoxy-6a,12a-dehydrodeguelin were isolated from the twigs of Millettia duchesnei, together with the known compounds, 6a,12a-dehydrodeguelin, ... -
Stereoselective routes to 3-hydroxy and 3,4-dihydroxy derivatives
(Elsevier Ltd; www.elsevier.com/locate/tetlet, 2004-06-21)The Diels-Alder adduct of ethyl (E)-3-nitroacrylate and furan provides a versatile template for the stereoselective synthesis of mono and dihydroxylated derivatives of 2-aminocyclohexanecarboxylic acid (ACHC). The ... -
Antimicrobial activity of the crude extracts and five flavonoids from the twigs of Dorstenia barteri (Moraceae)
(Elsevier Ireland Ltd. http://www.elsevier.com/wps/find/journaldescription.cws_home/506035/description#description, 2008)The aim of this study was to evaluate the antimicrobial activity of the crude extract of the twigs of Dorstenia barteri (DBT) as well as that of four of the five flavonoids isolated from this extract. Gram-positive bacteria ... -
Work in Thermodynamics
(Chemic Publishing Co., http://www.asianjournalofchemistry.com/, 2006)The expression for mechanical work obtained in the expansion of a gas commonly used in physical chemistry textbooks is critically examined. The mathematical form of the first law of thermodynamics is arrived at by a procedure ... -
Antibacterial Diterpenes from the Roots of Ceriops tagal
(Natural Product Inc. http://www.naturalproduct.us/, 2008)Investigation of the roots of Ceriops tagal led to the isolation of a new isopimarane, together with the known diterpenes isopimar-8(14)-en-15,16-diol and erythroxyl-4(17),15(16)-dien-3-one. The structure of the new ... -
Antimicrobial and radical scavenging flavonoids from the stem wood of Erythrina latissima
(Elsevier Ltd; http://www.elsevier.com/wps/find/journaldescription.cws_home/273/description, 2004-11-20)From the stem wood of Erythrina latissima, two isoflavones and a flavanone were isolated and characterized as 7,3'-dihydroxy-4'-methoxy-5'-(y,y-dimethylallyl)isoflavone (erylatissin A), 7,3'-dihydroxy-6".6"-dimethyl-4".5 ... -
Evaluation of methods for the isolation, detection and quantification of cyanobacterial hepatotoxins
(Elsevier Ltd. http://www.elsevier.com/wps/find/journaldescription.cws_home/505509/description#description, 2006)Cyanobacterial hepatotoxins such as microcystins and nodularins have been responsible for the poisoning of both animals and humans who ingest or come into contact with toxic blooms. They are extremely stable in water due ...