Isolation and Selective Glycosylation of Antisalmonellal Anthraquinones From the Stem Bark of Morinda Lucida Benth. (Rubiaceae)

In this work we report the isolation, identification and antibacterial activity of two anthraquinones, 2-hydroxy-1-methoxyanthraquinone (1) and 2,5-dihydroxy-1-methoxy-6-methoxymethylanthraquinone (2), from the stem bark of Morinda lucida. These two natural products were selectively converted into two new glycosylated derivatives, 2-hydroxy-1-methoxyanthraquinone-4′-O-methyl-2-O-β-d-glucopyranoside (3) and 2,5-dihydroxy-1-methoxy-6-methoxymethylanthraquinone-4′-O-methyl-2-O-β-d-glucopyranoside (4) by the filamentous fungus Beauveria bassiana ATCC 7159. Structure elucidation was accomplished based on the 1D and 2D NMR, IR and mass spectra. The glycosylated compounds 3 and 4 showed higher in vitro antibacterial activity against Salmonella enterica subsp. enterica sérovars Typhimurim (MIC of 8 μg/mL each) than the corresponding aglycons 1 and 2 (MIC of 16 μg/mL and 32 μg/mL, respectively). These results indicated that microbial glycosylation is an effective approach to modify natural products for enhanced biological activities

Contribution to the ethnobotanical inventory of medicinal plants used for the treatment of typhoid fever in Adamaoua region, Cameroon

Since ancient Greek-Roman times, the use of plants to cure many human diseases is still common. The present ethnobotanical survey was conducted to contribute to the knowledge of medicinal plants used for the treatment of typhoid fever in three sub divisions of Vina division, Adamawa Cameroon. After having explained the importance of this study to interviewees, 41 traditional healers have agreed and delivered information regarding the medicinal plants they use as well as the different preparation and administration through a well- structured questionnaire that was given to them on this matter. Among 41 traditional healers whose attended this study, 32 were men and 09 were women. The ethnobotanical survey allowed the identification of 70 plants belonging to 38 families. With a frequency of 11/70, the Fabaceae family was the most represented followed by that of Rubiaceae and Asteraceae (04/70 each). The leaves are the most used parts (34.28%) followed by leaves + roots (14.28%) and the whole plant (12.86%). The majority of the recipes consisted of four to six plants (34.66), and were prepared by decoction (50%), with water as the main solvent (87.80%). 41.56% of typhoid preparations are administered twice daily for a duration of 14 days (46.77%). This is the first report on antityphoid herbal remedies in Vina division-Adamawa Cameroon. It would therefore be judicious for our government and research institution to investigate on their therapeutic properties in order to develop ameliorated and efficient phytomedicines

Epidémiologie moléculaire du rotavirus du groupe A associé aux gastroentérites chez les enfants de moins de 5 ans dans la ville de Yaoundé (Cameroun)

Le rotavirus est la première cause de gastroentérites grave chez les enfants de moins de 5 ans. La gravité et la mortalité de la maladie sont majorées dans les pays à revenus faibles d’Asie du sud et d’Afrique subsaharienne. Au Cameroun, la forte prévalence des rotaviroses, associées aux spécificités génotypiques locales du virus, soulignent l’importance de disposer de données épidémiologiques sur le virus. Cette étude visait à contribuer à une meilleure connaissance des principales souches de rotavirus responsables des gastroentérites chez les enfants de moins de 5 ans dans la ville de Yaoundé. Il s’agit d’une étude descriptive transversale d’une durée de 4 mois, dans 8 formations sanitaires de la ville de Yaoundé. Les échantillons de selles d’enfants de moins de 5 ans, hospitalisés pour gastroentérite ont été prélevés. La recherche du rotavirus s’est faite avec le kit ELISA Oxoid ProSpec TTM, et la détermination des génotypes du virus s’est faite par RT - PCR. Cent trente échantillons de selles d’enfants souffrant de gastroentérite ont été collectés. 66,1% de ces échantillons provenaient des hôpitaux FCB/CME, du CHE et de HDE. Le rotavirus a été isolé chez 30% des enfants, dont 40% avait entre 6 et 11 mois. Le CHE (6,9%) et l’HGY (0%) avaient respectivement la prévalence la plus élevée et la plus basse de la ville. Un nombre élevé de combinaisons génotypiques a été isolé, parmi lesquels prédominaient G1P[8] (31%) suivit de G3P[6] (28%) et de G4P[6] (13 %). Les génotypes mixtes G1P[6][8], G2P[6][8], et G1G3P[8] représentaient 22% des isolats. Un type G (3%) est resté indéterminé durant cette étude.© 2015 International Formulae Group. All rights reserved.Mots clés: Epidémiologie moléculaire, rotavirus, génotypes, gastroentérite, enfants, YaoundéEnglish Title:  Molecular epidemiology of group A rotavirus associated to gastroenteritis in children less than 5 years in Yaoundé (Cameroon)English AbstractRotavirus is the leading cause of severe gastroenteritis in children less than 5 years. Severity and mortality of this disease are majored in low-income countries of South - Asia and sub - Saharan Africa. In Cameroon, the high prevalence of rotaviruses associated to local genotypic specificities of virus enhances the importance of epidemiological database on the virus. This study aimed at contributing to a better knowledge of the main rotavirus strains responsible for gastroenteritis in children less than 5 years in Yaoundé. We carried out a descriptive and cross sectional study during 4 months, in 8 health centers in Yaoundé. Stool specimens were collected from children less than 5 years old, hospitalized for gastroenteritis. Rotavirus was detected with ELISA kit Oxoid ProSpecTTM, and genotypes determined by RT - PCR. One hundred and twenty seven stool specimens were collected during the study. FCB/CME, CHE, HDE provided 66.1% of specimens collected. Rotavirus was isolated in 30% of children, and 40% of these children were between 6 to 11 months old. The CHE (6. 9%) and the HGY (0%) had respectively the highest and the lowest prevalence of the town. A large number of genotype has been isolated and G1P[8] (31%) were predominant, followed by G3P[6] (28%) and G4P[6] (13%). Mixt genotypes G1P[6][8], G2P[6][8], and G1G3P[8] represented 22% of isolates. One G - type remained untypable.© 2015 International Formulae Group. All rights reserved.Keywords: Molecular epidemiology, rotavirus, genotypes, gastroenteritis, children, Yaound

Antisalmonellal Activities of Extracts, Fractions, Compounds and Semi-synthetic Flavonoid Derivatives from Tristemma hirtum P. Beauv (Melastomataceae)

The development and spread of resistance to currently available antibiotics is a major drawback in the treatment of microbial infections. Salmonellosis for example remains among the most common cause of morbidity and mortality in developing countries. This study aimed to evaluate the antisalmonellal potential of extracts, fractions, isolated compounds and semi-synthetic flavonoids from Tristemma hirtum P. Beauv. Bioguided fractionation by column chromatography of the EtOAc and n-BuOH fractions led to the isolation of eleven compounds including two new esterified glucuronide flavonoids namely: luteolin-3′-O-β-D-glucuronopyranosylbutyl ester (1), a mixture of compound 1 and quercetin-3-O-β-D-glucuronopyranosylbutyl ester (2). Chemical transformation mainly based on the prenylation of 6-hydroxyapigenin-7-O-β-D-glucopyranoside (5) afforded four new semi-synthetic flavonoid derivatives namely: 6, 4'-O-diprenylapigenin-7-O-β-D-glucopyranoside (5a), 8-Cprenyl- 6, 4'-O-diprenylapigenin-7-O-β-D-glucopyranoside (5b), 8-C-prenyl-4'-O-prenylapigenin-7-O-β-D-glucopyranoside (5c), 4'-O-prenylapigenin-7-O-β-D-glucopyranoside (5d). The chemical structures of these compounds were assigned using NMR techniques, mass spectrometry and by comparison of their data with reported ones. The antisalmonellal activity was assessed by determining the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) using serial microdilution methods. The results showed that the MeOH extract and EtOAc fraction were active against all the bacteria tested with MICs ranging from 24 to 1536 μg/mL. Seven isolated compounds and three semi-synthetic compounds tested showed MIC values ranging from 16 to 256 μg/mL. Compounds 1, 3, 5a, 5c and 11 displayed the most potent antisalmonellal properties but were generally less potent than those of reference drugs. The activity of extracts and isolated compounds could be used as the starting point for the development of alternative phytodrugs against salmonellosi

ANTIBACTERIAL AGENTS FROM THE SEEDS OF PEUCEDANUM ZENKERI L. (UMBELLIFERAE)

ABSTRACT Objective: In a search for natural substances with potential for the treatment of typhoid fevers and urogenital infections, the methylene chloride extract of the seeds of Peucedanum zenkeri was investigated. Methodology: The extract was subjected to column chromatography leading to the isolation of seven compounds. Their structures were determined using modern 2D NMR techniques and by comparison with published NMR data. These compounds were tested against Salmonella typhi, Salmonella paratyphi B, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus, using both agar diffusion and broth dilution techniques. Results: The compounds isolated were umbelliprenin (1), prangenin (2), imperatorin (3), isopimpinellin (4), bergapten (5), cnidilin (6) and stigmasterol (7). Among the above seven compounds, only two (1 and 2) exhibited antibacterial activity. For compound 1, the MIC value was 300 µg/ml against P. aeruginosa, S. aureus, S. typhi and S. paratyphi B. For compound 2, the MIC values varied between 200 and 300 µg/ml against all the bacteria strains tested. Conclusion: These data suggest that Peucedanum zenkeri seed extract contains antibacterial agents which are active against Salmonella species causing typhoid and paratyphoid fevers, and some bacteria strains causing urogenital infections. The antibacterial activity of compound 2 appears to be due to the epoxide group present in its structure

Variabilité des caractéristiques physiques des mangues cultivées au Tchad: caractérisation de la diversité fonctionnelle

Objectif: Le Tchad produit plus de 14 variétés de mangues, de caractéristiques physiques cependant peu connus. L’étude avait pour objectif de déterminer les caractères physiques de ces variétés de mangues afin de contribuer à leur vulgarisation et valorisation.Méthodologie et résultats: Les données physiques ont été collectées sur chaque fruit de mangue dans un échantillon constitué de 15 fruits mûrs d’une variété, récoltés sur trois manguiers dans un verger. L’ensemble des fruits ont été récoltés dans 12 vergers repartis dans les quatre régions d’étude. Cette étude a montré que les variétés de mangues Davis haden, Smith, Eldon, Kent et Coeur de Boeuf cultivées au Tchad et particulièrement dans la région du Logone Occidental avaient les meilleurs paramètres physiques notamment la masse, le volume, l’indice de calibre, la masse de la pulpe et le rendement de la pulpe. Par contre les variétés locales (Bangui, Kassaï et Mangotine) avaient les paramètres les plus modestes excepté la variété Maïduguri, qui est classée parmi les variétés moyennes avec José Tchad, Julie Kassawa, Keitt, Palmer et Valencia, mais toutefois avait la meilleure qualité commerciale (proportion de la pulpe : 83,26±2,36%). Les variétés locales avaient néanmoins une fermeté plus élevée (2,33±0,38 à 2,46±0,33) par rapport aux variétés améliorées (2,11±0,29 à 2,39±0,23). Toutes ces variétés de mangues étaient de forme allongée et avaient un poids spécifique proche de celui de l’eau à l’état mûr (0,99±0,01 à 1,12±1,02). Chez toutes ces variétés de mangue, une corrélation positive parfaite (r = 1) a été trouvée entre la masse de la mangue et la masse de la pulpe.Conclusions et applications des résultats: Il ressort de cette étude qu’il y a une importante variabilité des caractéristiques morphologiques et physiques entre les variétés et qu’ils sont milieu-dépendants. Les variétés améliorées se distinguent nettement des variétés locales par l’importance de ces paramètres. Les résultats obtenus permettraient d’apprécier les potentialités adaptatives des variétés de mangues et fourniraient des informations nécessaires aux différents acteurs de la filière mangue en vue de rationaliser le choix des variétés de mangues. Ils pourraient permettre notamment le tri des fruits mûrs des non mûrs car les fruits mûrs ont un poids spécifique proche de l’unité, donc flottable sur l’eau. Enfin, ces résultats  montrent que la variabilité des paramètres étudiés résulterait d’une diversité fonctionnelle des mangues cultivées au Tchad.Mots clés: Variétés de mangues, caractères physiques, diversité fonctionnelle, Tchad et régions de cultureEnglish Title: Variability of physical characteristics of mangoes cultivated in Chad: characterization of the functional diversityEnglish AbstractObjective: Chad produces more than 14 varieties of mangoes; however, their physicals characteristics are little known. The aim of the study was to determine the physical characteristics of these varieties of mangoes in order to contribute to their popularization and valorization.Methodology and results: Physical data were collected from each mango fruit in a sample of 15 ripe fruits of one variety harvested from three mango trees in an orchard. All fruits were harvested from 12 orchards in the four study regions. This study showed that Davis haden, Smith, Eldon, Kent and Coeur de Boeuf mango varieties cultivated in Chad and particularly in the region of Logone Occidental had the best physical parameters including mass, volume, index of caliber, the mass of the pulp and the pulp yield. On the other hand, the local varieties (Bangui, Kassaï and Mangotine) had the most modest parameters except the variety Maïduguri, which is classified among the medium varieties group with José Tchad, Julie Kassawa, Keitt, Palmer and Valencia, but nevertheless possessed the best commercial quality (pulp proportion: 83.26 ± 2.36%). Local varieties had higher firmness (2.33 ± 0.38 to 2.46 ± 0.33) than improved varieties (2.11 ± 0.29 to 2.39 ± 0.23). All these varieties of mangoes grown in Chad were elongated and had at ripe stage a specific weight nearly to 1 (0.99 ± 0.01 to 1.12 ± 1.02). In all these varieties of mango, a perfect positive correlation (r = 1) was found between the mass of the mango and the mass of the pulp.Conclusions and applications of the results: This study showed that there is a great variability of morphological and phycical characteristics between varieties and that they are milieu-dependent. The improved varieties were clearly distinguishable from local varieties by the importance of morphological and physical parameters. The results obtained would allow an appreciation of the adaptive potential of mango varieties and provide the necessary informations to the various actors in the mango sector in order to rationalize the choice of mango varieties. They could in particular allow the sorting of mature and ripe fruits because the ripe fruits have a specific weight nearly to unit, therefore floatable on water. Finally, these results indicated that the variability of parameters studied could be a result of a funtional diversity of mango varieties cultivated in Chad.Keywords: Mango varieties, physical characters, functional diversity, Chad and cultivation region

Biochemical Characteristics of Mangoes Cultivated in Chad: Characterisation of the Functional Diversity

Mango is one of the most consumed fruits in Chad and several varieties are cultivated there. However, their biochemical characteristics are still unknown. The objective of this study was to determine the biochemical characteristics of mango varieties cultivated in Chad. Moisture, dry matter, chlorophyll a, chlorophyll b, lycopene b-carotene contents, pH and total soluble solids were determined in ripened mango fruits with firmness between 2 and 3 kgf. The results showed that Mangotine, José Tchad and Bangui mango varieties had a significantly higher total soluble solids (19.37 to 20.86°Brix) and dry matter content (24.57 to 25.48%), while Maïduguri, Kent and Smith varieties were richer in water (80.20 to 80.75%). The José Tchad variety also had the highest pH (4.74) and the highest b-carotene content (0.11 mg/10 g). The peels of all varieties of mangoes were richer in b-carotene than their pulp. Lycopene was found in the peel and pulp of some mango varieties, and the peel of Mangotine contain more lycopene than the pulp. The results indicated a functional diversity of Chad mango varieties as related to some biochemical features. Furthermore, besides the pulp, the peel of these fruits could be considered as an important alternative source of b-carotene, a precursor of vitamin A