Status of research results in chemistry of biologically active substances in Benin

Research on biologically active chemicals extracted from medicinal plants and essential oils from aromatic plants in the West African subregion is booming. Recognition of the clinical, pharmaceutical and economic value of herbal medicines continues to grow despite the growth of the pharmaceutical industry and the continued development of new, more effective synthetic and biological medical products. On the other hand, despite the improvement in food preservation technics, food preservatives nature remains one of the most important issues for public health. Indeed, several synthetic preservatives have been banned in some countries because of their long-term adverse toxicological effects. The current trend of consumers to seek for a more natural diet has prompted the research, development and application of new natural products with antimicrobial and antioxidant activities in order to use them as alternatives to synthetic preservatives. This review aims to do an inventory of the results of research in chemistry of biologically active substances in Benin

PHYTOCHEMICAL STUDY OF A TINCTORIAL PLANT OF BENIN TRADITIONAL PHARMACOPOEIA: THE RED SORGHUM (Sorghum caudatum) OF BENIN

The full phytochemical screening of red sorghum from Benin (Sorghum caudatum) achieved in this work reveals the presence of leucoanthocyanins, flavonoides, free quinones, combined anthracene derivatives, sterols and terpenes in higher concentration in the leaf sheath and marrow of stem than in the seed. Catechin tannin content is 11.4% in the leaf sheath (slightly higher than that of red wine), 5.8% in the marrow and 2.8% in the seed. Gallic tannins, saponins and the mucilage present in the leaf sheath and marrow, are virtually absent in the seed. Marrow and leaf sheath extracts (1 g/50 mL) showed a concentration of anthocyanins (147 mg/L and 213.5 mg/L) similar to that of rosy wine and red wine with short maceration. The grain of sorghum is four times, respectively two times less rich in phenolic compounds than the leaf sheath and the marrow of stem

Effet des prétraitements post-récolte des amandes de Pentadesma butyracea (Sabine) sur la technologie d’extraction en milieu réel et la qualité du beurre

Pentadesma butter is still traditionally extracted starting from pretreated almonds by traditional techniques of heating. The aim of this work was to study the effect of the almonds post-harvest pretreatments on the physicochemical characteristics, the extraction yield and the quality of the Pentadesma butter. In addition, the effect of the various unit operations of the extraction technology on the quality of the extracted butter from pretreated almonds was studied. According to the same traditional process of extraction, two various butters of Pentadesma were extracted starting from almonds differing only by the post-harvest pretreatment applied (roasting or boiling). The color, the aspect and the breaking strength of the almonds were different. The butter extraction yield varied according to the pretreatment applied. The best yields (33.5 ± 4.1%) were obtained from boiled almonds, but their transformation was more difficult than that of roasted. The analysis of the samples at different stages of the transformation allowed the appreciation of the effect of the almonds pretreatments on the acidity and the peroxide value variations at each unit operation of the butter extraction. The fatty acid composition and the tocopherol content of the two extracted butters varied with the almonds pretreatments. The roasted almonds provided a richer butter in stearic acid, a and d-tocopherols and less rich in oleic acid than that provided by the boiled almonds. The pretreatments allowed a total loss of the contained linolenic acid, b and dtocopherols in the butters and decreased the oleic acid and a- tocopherol contents. The physico-chemical characteristics of the Pentadesma butter varied according to the almonds pretreatments. Thus, it would be interesting to make a reasoned choice of the most suitable post-harvest pretreatment in order to obtain a butter with a good quality and an acceptable extraction yield

Efficacité des huiles essentielles de trois plantes aromatiques contre la mycoflore d’altération du niébé (Vigna unguiculata L., Walp) collecté dans les magasins de vente du Sud-Bénin

Objectif : La présente étude vise à évaluer l’activité antimicrobienne des huiles essentielles extraites des feuilles fraîches de Cymbopogon citratus (L.), de Cymbopogon nardus (L.), et de Eucalyptus saligna (S.), sur les moisissures isolées des stocks de niébé de quelques magasins de vente du sud-Bénin.Méthodologie et Résultats : Pour ce faire, un échantillonnage a été réalisé dans les grands magasins de stockage du niébé situés dans les marchés de Ouando (Porto-Novo) et de Dantokpa (Cotonou) suivi de la recherche et l’isolement de la mycoflore d’altération. Des tests antifongiques ont été réalisés avec les huiles essentielles de Cymbopogon citratus (L.), Cymbopogon nardus (L.), et de Eucalyptus saligna (S.), afin d’évaluer leur potentiel antifongique. Des résultats obtenus, il ressort que les souches fongiques isolées des échantillons de niébé sont essentiellement Aspergillus flavus (L.), Aspergillus tamarii (K.) et Penicillium roqueforti (T.). Les tests antifongiques ont permis de démontrer l’activité des huiles essentielles testées contre la flore fongique contaminant le niébé, avec des concentrations minimales d’inhibition (CMI) dépendantes du type fongique et de la dose d’huile essentielle testée. Les fortes activités antifongiques sont obtenues avec les huiles essentielles de Cymbopogon citratus (L.) et de Cymbopogon nardus (L.) avec des CMI comprises entre de 0,05 et 1Al/ml.Conclusion : Le potentiel antifongique de ces plantes offre donc une approche novatrice dans la gestion intégrée des stocks de niébé au Sud du Bénin.Mots clés : niébé, moisissures, huiles essentielles, activité antifongique

Comparative chemical study and cytotoxic activity of Uvariodendron angustifolium essential oils from Benin.

International audienceThis study aimed to compare the chemical composition of volatile extracts obtained by hydrodistillation of leaves, stems, bark and roots of Uvariodendron angustifolium (Engl. & Diels) R. E. Fries. The essential oils, obtained with yields between 0.12 and 0.66%, were analyzed by GC/FID and GC/MS. A great variability in the chemical composition was observed depending on the plant part treated. The essential oils obtained from leaves and stems contained mainly neral (29.7-30.5%) and geranial (42.9-47.3%), while methyl eugenol was the major component of the volatile extracts from bark (68.3%) and roots (85.3%). Interesting cytotoxic properties of these essential oils on human breast cancer cells MCF-7 were demonstrated