Emmanuel Mpondo

New furoquinoline alkaloid and flavanone glycoside derivatives from the leaves of Oricia suaveolens and Oricia renieri (Rutaceae)

Fractionation of the methanol extract of the leaves of Oricia renieri and Oricia suaveolens (Rutaceae) led to the isolation of 13 compounds including the hitherto unknown furoquinoline alkaloid named 6,7-methylenedioxy-5-hydroxy-8-methoxy-dictamnine (1) and a flavanone glycoside named 5-hydroxy-4′-methoxy-7-O-[α-l-rhamnopyranosyl(1‴→5″)-β-d-apiofuranosyl]-flavanoside (2), together with 11 known compounds (3–13). The structures of the compounds were determined by comprehensive analyses of their 1D and 2D NMR, mass spectral data and comparison. All compounds isolated were examined for their activity against human carcinoma cell lines. The alkaloids 1, 5, 12, 13 and the phenolic 2, 8, 11 tested compounds exhibited non-selective moderate cytotoxic activity with IC50 8.7–15.9 μM whereas compounds 3, 4, 6, 7, 9 and 10 showed low activity.

Unexplored vegetal green synthesis of silver nanoparticles: A preliminary study with Corchorus olitorus Linn and Ipomea batatas (L.) Lam

Antibacterial properties of silver ion are known from ancient times. The plant extract mediated synthesis of nanoparticles is gaining popularity due to green chemistry for the generation of nanosized materials. Corchorus olitorus Linn and Ipomea batatas (L.) Lam are world crops having leaves of high nutritional value. In the present work, Ag and AgCl nanoparticles were synthesized by incubating leaf aqueous extracts with silver nitrate salt, making them to react in the dark. Plasmon resonance bands, studied by ultraviolet spectroscopy, have been obtained. X-ray diffraction (XRD) revealed the average size of pure crystallites composed of Ag and AgCl. Optimization studies for the synthesis process highlight positive impact of pH, reaction time and reactants quantities. Key words: Silver, nanoparticles, Corchorus olitorus , Ipomea batatas , X-ray diffraction.

Natural Substances for the Synthesis of Silver Nanoparticles against Escherichia coli

The development of drug-resistant strains is rising and the search for new and novel ways of fighting new or reemerging microbes goes on. A hope of treating such multidrug-resistant infections came from plants mediated nanoparticles since nature is a generous source which provides a variety of chemical compounds that can be used for new drug discovery. Silver nanoparticles are reported to possess antiviral, antibacterial, antifungal, antiparasitic, larvicidal activity and anticancer properties. We reported green synthesis of silver nanoparticles mediated food plants Megaphrynium macrostachyum, Corchorus olitorus, Ricinodendron heudelotii, Gnetum bucholzianum, and Ipomoea batatas and their antibacterial efficacy against the Enterobacteriaceae Escherichia coli. The nature and size of the obtained nanoparticles are discussed as well as their Minimum Inhibitory Concentration (MIC) and the Minimum Bactericide Concentration (MBC) values considering their application in medical industry.

Characterization of pharmaceutical medication without a medical prescription in children before hospitalization in a resource-limited setting, Cameroon

Introduction The use of different therapeutic approaches is common among sick children in Cameroon. The main objective of this study was to characterize the use of non-prescription drugs and describe the therapeutic itineraries of sick children before admission to the hospital. Methods A cross-sectional and prospective study was conducted from January to May 2017. A closed-ended questionnaire (CEQ) consisting of one or several response options was administered to the parents/guardians of the children on admission to the hospital in the pediatric ward of the Laquintinie Hospital in Douala (LHD) and the Cité des Palmiers District Hospital (CPDH) of the city of Douala. Inclusion of participants was made consecutively for adolescents who gave their consent and parents or guardians who signed the informed consent for all children. The confidentiality of the data was ensured by the replacement of the names by codes. Results Overall, 295 hospitalized children were included with an average age of 3.1 (SD: 3.3) years in the study. More than half of these children (58.6%) came from LHD. More than 90% of parents had at least one therapeutic recourse (TR). The ratio of boys to girls 3/1. Self-medication (74.1%) and medical consultation (16.9%) were the main therapeutic paths in 1st recourse. The medical consultation (80.2%) and the pharmaceutical advice (16.9%) were used frequently in 2nd recourse. The mean lapse time to see a medical professional was 2.7 days (min-max: 0-14 days). The main symptoms associated with TR were fever (76.6%), vomiting (24.7%) and diarrhea (22.7%). The most frequently used drugs were Analgesics/antipyretics (47.6%), antimalarials (15.0%) and antibiotics (10.2%) and the family medicine box was the highest source of drugs. Conclusion Self medication remains the first therapeutic path, followed by medical consultation as second therapeutic path taken when the disease is perceived as serious.

Connaissances et usages traditionnels des plantes médicinales du département du haut Nyong

Objectif : Dans le but de contribuer a la connaissance de certaines plantes medicinales et a leurs usages traditionnels sur certains symptomes, une enquete a ete realisee dans trois villages du departement du Haut Nyong (region de l’Est). Materiel et Resultats : L’enquete s’est effectuee aupres de 90 personnes sans distinction d’âge et de sexe. Celles-ci ont ete soumises a un questionnaire donnant toutes les informations relatives aux plantes medicinales en langue francaise ou locale (maka’a). Les donnees concernant les details des recettes ont ete collectees selon les fiches proposees par la banque de donnees de medecine traditionnelle et pharmacopee (PHARMEL). Les echantillons ont ete recoltes et conserves selon la technique de Schnell. L’identification s’est faite a l’Herbier National du Cameroun. Les donnees recueillies ont ete analysees statistiquement et traitees par le logiciel XLSTAT. Les caracterisations ecologiques puis pharmacologiques des especes vegetales ont ete realisees via la revue bibliographique. Quatre-vingt-dix especes vegetales au total ont ete identifiees et reparties en 83 genres et 47 familles, la plus representee a ete celle des Euphorbiaceae (10 especes). Les types phytogeographiques afrotropicales ont ete les plus cites. Les sarcochores ont ete les types de diaspores dominants et la zoochorie a ete le mode de dissemination le plus repandu. Seulement deux plantes recensees montrent une frequence de citation superieure ou egale a 50% ; il s’agit de Euphorbia hirta (51%) et Manihot esculenta (51%). Les especes recensees entrent dans la preparation de 100 recettes. La decoction a ete le mode de preparation le plus pratiquee, et la feuille l’organe vegetal le plus utilise. Les plantes citees pourraient contenir pour la plupart des alcaloides, les tanins et les flavonoides. Conclusion et Application des resultats : La valorisation de ces plantes et la determination du profil de sante des populations locales du departement du Haut-Nyong necessite la mise en place des unites de transformations modernes specialisees dans la fabrication des nouveaux medicaments. Mots cles : Ethnobotanique, ethno pharmacologique, frequence de citation, plantes medicinales, metabolites secondaires

Protease-inhibiting, molecular modeling and antimicrobial activities of extracts and constituents from Helichrysum foetidum and Helichrysum mechowianum (compositae)

AbstractBackgroundHelichrysum species are used extensively for stress-related ailments and as dressings for wounds normally encountered in circumcision rites, bruises, cuts and sores. It has been reported that Helichysum species are used to relief abdominal pain, heart burn, cough, cold, wounds, female sterility, menstrual pain.ResultsFrom the extracts of Helichrysum foetidum (L.) Moench, six known compounds were isolated and identified. They were 7, 4′-dihydroxy-5-methoxy-flavanone (1), 6′-methoxy-2′,4, 4′-trihydroxychalcone (2), 6′-methoxy-2′,4-dihydroxychalcone -4′-O-β-D-glucoside (3), apigenin (4), apigenin-7-O-β-D-glucoside (5), kaur-16-en-18-oic acid (6) while two known compounds 3,5,7-trihydroxy-8-methoxyflavone (12), 4,5-dicaffeoyl quinic acid (13) together with a mixture of phytosterol were isolated from the methanol extract of Helichrysum mechowianum Klatt. All the compounds were characterized by spectroscopic and mass spectrometric methods, and by comparison with literature data. Both extracts and all the isolates were screened for the protease inhibition, antibacterial and antifungal activities. In addition, the phytochemical profiles of both species were investigated by ESI-MS experiments.ConclusionsThese results showed that the protease inhibition assay of H. foetidum could be mainly attributed to the constituents of flavonoids glycosides (3, 5) while the compound (13) from H. mechowianum contributes to the stomach protecting effects. In addition, among the antibacterial and antifungal activities of all the isolates, compound (6) was found to possess a potent inhibitor effect against the tested microorganisms. The heterogeneity of the genus is also reflected in its phytochemical diversity. The differential bioactivities and determined constituents support the traditional use of the species. Molecular modelling was carried out by computing selected descriptors related to drug absorption, distribution, metabolism, excretion and toxicity (ADMET). Graphical abstractCompounds isolated from Helichrysum species (Compositae).