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Abidjan, Ivory Coast

Dobo M.,University of Abobo Adjame | Ayres N.,Texas A&M University | Walker G.,Texas A&M University | Park W.D.,Texas A&M University
Journal of Cereal Science | Year: 2010

The present study was conducted to investigate the relationship between waxy allelic forms and amylose in European and US rice germplasm. These allelic forms were defined according to the single-nucleotide polymorphisms (SNP) found in the leader intron 5′ splice site (G → T), exon 6 (A → C) and exon 10 (C → T). The combination of these three SNPs accounted for 89.2% of the variation in apparent amylose content in a pedigree of 85 US rice varieties and 93.8% of the variation among 279 accessions in a European germplasm collection. The allelic forms TAC and TCC were found in low amylose varieties. All varieties with intermediate levels of apparent amylose had the GCC allele. High levels of apparent amylose varieties had either the GAT and GAC allele. The sequence AG. TTATA in the intron 1 distinguished the low amylose varieties from the other classes regardless of any other base changes. Intermediate amylose varieties can be distinguished from those with high apparent amylose by changes in either exon 6 or exon 10. However the simplest interpretation of the data is that the tyrosine/serine change in exon 6 is responsible for the lower levels of Granule bound starch synthase (GBSS) protein and thus lower levels of amylose in intermediate vs. high amylose verities. © 2010 Elsevier Ltd.

Ntie-Kang F.,University of Douala | Ntie-Kang F.,University of Buea | Ntie-Kang F.,Martin Luther University of Halle Wittenberg | Kannan S.,Martin Luther University of Halle Wittenberg | And 6 more authors.
Molecular BioSystems | Year: 2014

Recently, the search for new drugs against tuberculosis (TB) has been a hot topic and the search for new inhibitors against validated drug targets and pathways other than those currently targeted by known drugs is suggested to be the most promising way forward. Mycobacterium tuberculosis pantothenate synthetase (MTBPS) happens to be one of such targets. In a quest to carry out virtual screening for active inhibitors against MTBPS and to get ideas for the design of new inhibitors against this target, we have docked a set of pyrazole-based inhibitors to the active site of this enzyme. The docking solutions were post processed using the MM-PB(GB)SA method and molecular dynamic simulations in order to analyze and validate the two previously proposed binding modes. The results show that both the MM-PBSA and MM-GBSA were able to discriminate between active and inactive compounds. Moreover, the pharmacophore-based scoring method proved efficient in discriminating the active compounds from inactives. From this work a protocol for screening of potential inhibitors of the enzyme from commercially available databases has been devised. © 2014 The Royal Society of Chemistry.

Dosso K.,University of Abobo Adjame
African journal of traditional, complementary, and alternative medicines : AJTCAM / African Networks on Ethnomedicines | Year: 2012

Piliostigma reticulatum (Caesalpiniaceae) is used in Africa as a traditional medicine for the treatment of many diseases, such as malaria, tuberculosis and diarrhoea. We investigated the antidiarrhoeal properties of a crude ethanol extract from the stem bark of Piliostigma reticulatum (EEPR) in Wistar albino rats to substantiate its traditional use and to determine its phytochemical constituents. The antidiarrhoeal activity of the plant extract was evaluated in a castor oil-induced diarrhoea model in rats and compared with loperamide. The effect of the extract on gastrointestinal motility was also determined by the oral administration of charcoal meal and castor oil-induced intestinal fluid accumulation (enteropooling). EEPR showed remarkable dose-dependent antidiarrhoeal activity evidenced by a reduction of defecation frequency and change in consistency. Extracts at 250, 500 and 1000 mg/kg body weight significantly reduced diarrhoeal faeces. EEPR also significantly inhibited gastrointestinal motility and castor oil-induced enteropooling at 500 and 1000 mg/kg, similar to the inhibition obtained in control rats treated by atropine. Phytochemical screening revealed the presence of tannins, flavonoids, polyphenols and reducing sugars in the stem bark of P. reticulatum. No mortality or visible signs of general weakness were observed in the rats following administration of the crude extract in doses up to 6000 mg/kg body weight in an acute toxicity study. Our results show that the stem bark of P. reticulatum possesses antidiarrhoeal activity and strongly suggest that its use in traditional medicine practice could be justified.

The determination of the uronic acid content of biological and food substances is of primary importance when their functionalities are being investigated. To date, three kinds of colorimetric-H 2SO 4 procedures using carbazole, meta-hydroxydiphenyl, and 3,5-dimethylphenol chromogenic compounds are the most currently used to achieve this goal. However, great discrepancies in inter- and intra-procedure data are frequently noted in the literature for the same kinds of raw materials. A scrutiny of a large number of published procedures in combination with personal communication have permitted us to find out several potential results "modifiers," i. e., the experimental parameters, which modification alone, even slight, can engender significant variations in the final data, compared with the data from the original procedure. No less than a dozen factors have been pin-pointed as critical and discrepancy causing. Therefore, unreliable modification of a parameter at once without concomitant optimization of all the main parameters should completely be avoided. © 2011 Springer Science+Business Media, LLC.

Ntie-Kang F.,University of Douala | Ntie-Kang F.,University of Buea | Ntie-Kang F.,Martin Luther University of Halle Wittenberg | Onguene P.A.,University of Douala | And 6 more authors.
RSC Advances | Year: 2014

We assess the medicinal value and "drug-likeness" of ∼3200 compounds of natural origin, along with some of their derivatives which were obtained through hemisynthesis. In the present study, 376 distinct medicinal plant species belonging to 79 plant families from the Central African flora have been considered, based on data retrieved from literature sources. For each compound, the optimised 3D structure has been used to calculate physicochemical properties which determine oral availability on the basis of Lipinski's "Rule of Five". A comparative analysis has been carried out with the "drug-like", "lead-like", and "fragment-like" subsets, containing respectively 1726, 738 and 155 compounds, as well as with our smaller previously published CamMedNP library and the Dictionary of Natural products. A diversity analysis has been carried out in comparison with the DIVERSet™ Database (containing 48651 compounds) from ChemBridge. Our results prove that drug discovery, beginning with natural products from the Central African flora, could be promising. The 3D structures are available and could be useful for virtual screening and natural product lead generation programs. © 2014 The Royal Society of Chemistry.

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