Now showing items 1-10 of 62
3b-Taraxerol from Bridelia micrantha
Isolation of the title compound, C30H50O, from Bridelia micrantha yielded suitable crystals for an X-ray structure determination, showing it to be in the -form. The crystal packing is determined by infinite zigzag O—H ...
Photochromism, anomalous multi-banded fluorescence and laser properties of some amino- and tosyl-amino derivative of oxadiazole
(Elsevier 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 293 K are reported. All the compounds investigated ...
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 ...
Antimicrobial activity of the methanolic extracts and compounds from Treculia obovoidea (Moraceae)
(Elsevier Ireland Ltd. www.elsevier.com/locate/jethpharm, 2007)
The crude extract from Treculia obovoidea was subjected to purification by repeated chromatography. Eight compounds were isolated from Treculia obovoidea and identified as Psoralen (1), Bergapten (2), 7-methoxycoumarin ...
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 ...
Gaboroquinones A and B and 4'-O-demethylknipholone-4'-O-β-D-glucopyranoside, phenylanthraquinones from the roots of Bulbine frutescens
(American Chemical Society. http://pubs.acs.org/jnp/, 2002)
The novel phenylanthraquinones 4'-O-demethylknipholone-4'-O-β-D-glucopyranoside (2) and gaboroquinones A (3) and B (4) were isolated from the African medicinal plant Bulbine frutescens. Biaryl 2 represents the first ...
From nature, through chemical synthesis, toward use in agriculture: Oryzoxymycin case study
(International Union of Pure and Applied Chemistry. http://stage.iupac.org/publications/pac/, 2009)
The Diels–Alder adducts of ethyl (E)-3-nitroacrylate and furan provided a common and versatile template for the stereocontrolled synthesis of an isomer of the natural product oryzoxymycin and polyhydroxylated cyclohexyl ...
Stereoselective synthesis of 3,4,5,6-tetrahydroxycyclohexyl b-amino acid derivatives
(Elsevier Ltd. www.elsevier.com/ locate/tetlet, 2008)
Stereoselective syntheses of racemic (1S,2R,3R,4R,5S,6R)- and (1S,2R,3R,4S,5S,6R)-3,4,5,6-tetrahydroxy derivatives of 2-aminocyclohexanecarboxylic acid have been achieved by a stereospecific Diels–Alder reaction between ...
Influence of weak and strong donor groups on the fluorescence parameters and the intersystem crossing rate constant
(Elsevier Science Ltd. www.elsevier.com/locate/saa, 2003)
Please refer to the attached article for an ABSTRACT. The abstract was not uploaded here due to formula appearance problem in UBRISA.
Bivarate models: relationships between solar irradiation and either sunshine duration or extremum temperatures
(Elsevier Science Ltd. www.elsevier.com/locate/renene, 2003)
The Republic of Botswana is one of the sunniest countries in Southern Africa. It has very little cloud cover, insufficient rainfall, very low humidity, and very low wind speed throughout the year for most parts of the ...