HIGH PERFORMANCE LIQUID CHROMATOGRAPHY QUANTIFICATION OF OLEANOLIC ACID IN LAUNAEA TARAXACIFOLIA AND LARVICIDAL ACTIVITY AGAINST ANOPHELES GAMBIAE

Objective: One of the measures used to prevent malaria is the management of breeding sites. For preventive and ecologically profitable control, the use of bio-larvicides made from active plant extracts would be an asset for the control of malaria vectors, in particular Anopheles gambiae. Advances in pharmacognosy have revealed the benefits of several phytochemicals with very rich and varied therapeutic effects. Among the latter, oleanolic acid (OA) is quite remarkable because of its various and multiple properties, much of which is demonstrated with the leaves of Launaea taraxacifolia. Methods: After a liquid-liquid fractionation with different organic solvents of the hydro-methanolic extract of Launaea taraxacifolia, we obtained three fractions named Fhex (hexane fraction), FDCM (dichloromethane fraction) and FHM (hydro-methanolic fraction) which were tested on 3rd instar Anopheles gambiae larvae. Results: Fhex proved to be the most active with LC50 of 120.11 ppm and 69.50 ppm respectively in 24 and 48 hours of contact. We then developed a new method of Ultra-Violet High Performance Liquid Chromatography (HPLC / UV) method and determined the quantity of oleanolic acid in the Fhex and FDCM fractions to be respectively 0.46% and 0.23% . Conclusion: Launaea taraxacifolia has a larvicidal potential due to the presence of oleanolic acid whose inhibitory effect against Anopheles gambiae larvae

Maize Fungal Growth Control with Scopoletin of Cassava Roots Produced in Benin

The chemical contamination of food is among the main public health issues in developing countries. With a view to find new natural bioactive products against fungi responsible for chemical contamination of staple food such as maize, the antifungal activity tests of scopoletin extracted from different components of the cassava root produced in Benin were carried out. The dosage of scopoletin from parts of the root (first skin, second skin, whole root, and flesh) was done by High Performance Liquid Chromatography. The scopoletin extract was used to assess the activity of 12 strains (11 strains of maize and a reference strain). The presence of scopoletin was revealed in all components of the cassava root. Scopoletin extracted from the first skin cassava root was the most active both as inhibition of sporulation (52.29 to 87.91%) and the mycelial growth (36.51–80.41%). Scopoletin extract from the cassava root skins showed significant inhibitory activity on the tested strains with fungicide concentration (MFC) between 0.0125 mg/mL and 0.1 mg/mL. The antifungal scopoletin extracted from the cassava root skins may be well beneficial for the fungal control of the storage of maize

MARCHÉ OBLIGATAIRE DES TITRES PUBLICS ET INDUSTRIALISATION DANS L’UEMOA

Résumé : L’objectif de ce papier est d’analyser l’effet du marché obligataire des titres publics sur l’industrialisation en zone UEMOA. En nous appuyant sur un modèle linéaire pour les huit pays de l’UEMOA de 2005 à 2019. Nous avons utilisé la méthode des doubles moindres carrés avec variables instrumentales (DMC-VI/IV-2SLS). Elle établit une relation linéaire entre l’encours des titres publics et l’industrialisation en zone UEMOA. Le principal résultat obtenu suggère que l’encours des titres publics réduit le niveau d’industrialisation. Toutefois, des analyses spécifiques montrent que dans les sous-échantillons, l’effet négatif de l’encours des titres publics sur l’industrialisation est moins important pour les pays avec littoral comparativement au pays sans littoral. Classification JEL : E52- E58- H62- H63- H74 Mots-clés :Titres publics, marché obligataire, Industrialisation, dette publique, libéralisation financière Abstract : The aim of this paper is to analyse the effect of the government bond market on industrialisation in the WAEMU zone. We use a linear model for the eight WAEMU countries from 2005 to 2019. We used the double least squares method with instrumental variables (DMC-VI/IV-2SLS). It establishes a linear relationship between outstanding government securities and industrialisation in the WAEMU zone. The main result obtained suggests that the outstanding amount of government securities reduces the level of industrialisation. However, specific analyses show that in the sub-samples, the negative effect of outstanding government securities on industrialisation is less significant for landlocked countries than for landlocked countries. Keywords : government securities, bond market, industrialisation, public debt, financial liberalisatio

HPLC quantification of two isomeric triterpenic acids isolated from Mitracarpus scaber and antimicrobial activity on Dermatophilus congolensis

Oleanolic (OA) and ursolic acids (UA) were isolated for the first time from the alcoholic extract of Mitracarpus scaber possessing antimicrobial effects on Dermatophilus congolensis. These two triterpenic acids were also active (MIC 15 microg/ml) on this causative agent of dermatophilosis in African animals. To quantify OA and UA in M. scaber, a new, simple and rapid high-performance liquid chromatography (HPLC) method compatible with MS detection was developed and validated. The mobile phase acetonitrile:H2O (85:15, v/v) was pumped through a C18 octadecylsilyl silica column at a flow rate of 0.6 ml/min and the eluate was monitored at 215 nm. The calibration curves constructed between 0.5 and 10 microg/ml showed linear relationships with good R2 values. The developed method was precise and reproducible with relative standard deviations (RSD) for these two active constituents between 0.22-2.06% (intraday) and 1.61-3.72% (interday) for concentrations from 0.5 to 6 microg/ml. Limits of detection and quantification were, respectively, 0.2 and 0.5 microg/ml

Evolution des caractéristiques physico-chimiques de la graine et de l’huile de pourghère (Jatropha curcas) en fonction du degré de maturité des fruits

Jatropha curcas est l’une des espèces végétales identifiée dans les régions tropicales comme prometteuse pour la production d’huile végétale pure ou de biodiesel. L’influence du degré de maturité des fruits de pourghère sur la qualité de la graine et de l’huile a été évaluée afin d’élaborer les bonnes pratiques de récolte. Trois degrés de maturité ont été pris en compte : fruit vert-jaune, fruit entièrement jaune et fruit entièrement noir. Les paramètres physico-chimiques considérés sont la teneur en eau des graines, leur teneur en huile, l’acidité et la densité de l’huile. Les graines issues de fruits noirs ont présenté les caractéristiques les plus intéressantes avec une teneur en eau plus faible (9,25%), une teneur en huile plus élevée (42,59%) et une acidité de l’huile plus faible (3,9%). Les graines issues des deux autres types de fruit ont présenté des teneurs en eau élevées (> 25%), des teneurs en huile plus faibles (< 15%) avec des acidités de l’huile plus élevées (>25%) et des densités plus faibles (< 0,90). Les caractéristiques physico-chimiques de la graine et de l’huile se sont améliorées pendant la maturation du fruit et atteignent leurs meilleures valeurs au niveau des fruits noirs excepté la densité.© 2016 International Formulae Group. All rights reserved.Mots clés: pignon d’Inde, récolte, huile végétale pure, biodiesel, qualité de l’huile, BéninEnglish Title: Evolution of physico-chemical characteristics of seed and oil of jatropha (Jatropha curcas L.) depending on the degree of maturity of fruitEnglish AbstractJatropha curcas L. is one of vegetable species identified in tropical countries like promising for pure vegetable oil production or biofuel. The objective of this study is to evaluate the influence of physic nut fruit (Jatropha curcas) maturity degree on seed and oil quality so to work out good practice of harvest. Three degrees of maturity were taken into account: green-yellow, entirely yellow and entirely black fruit. The physicchemical parameters considered are seeds water content, seeds oil content, oil acidity and density. According to the fruit degree of maturity, seeds resulting from black fruits showed the most interesting characteristics with the lowest moisture content (9.25%), the highest oil content (42.59%) and the weakest oil acidity (3.9%). The seeds resulting from the two other types of fruits showed higher moisture contents (> 25%), lower oil contents (<15%) with higher oil acidities (> 25%) and weaker densities (< 0.90). The physicochemical characteristics of seed and oil evolve during fruit maturation and reach their best values for black fruits excepted oil density. Thus, in the absence of good method of drying, black fruit is the best stage of harvest for the production of pure vegetable oil of good quality.© 2016 International Formulae Group. All rights reserved.Keywords: Jatropha curcas, harvest, oil content, acidity, quality, Beni