Physicochemical Characterization of a Biodiesel Produced from Oil Extract from the Pulp of Raffia Sese de Wild Collected in Democratic Republic of Congo

Biodiesel are produced and characterized from the oil extract from the pulp of Raphia sese de Wild collected in Democratic republic of Congo. The transesterification reaction was used in homogeneous phase with acid and base catalysts. The reaction was carried out in volume ratio 6:1 of ethanol to oil using 1% in volume of the concentrated sulfuric acid (H2SO4) or sodium hydroxide (NaOH). The yield of the reaction was 73% in transesterified oil for the acid catalyzed reaction runned during 3 hours at 60°C, and 99.2% for the base catalyzed reaction runned during 2 hours, at the same temperature.   The physiochemical properties were determined for B100 (pure biodiesel), B10 and B5 (blended biodiesel with the fossil gazole). The results show that these three types of biodiesel can be used in a diesel engine in replacement of the traditional gazole

In vitro antiprotozoal activity and cytotoxicity of extracts and isolated constituents from Greenwayodendron suaveolens

Ethnopharmacological relevance The Nkundo people (Nkundo area of Bolongo, Mai-Ndombe district, Bandundu Province, DR Congo) use various plant parts of the tree Greenwayodendron suaveolens (Engl. Diels) Verdc. (syn. Polyalthia suaveolens Engl. Diels) (Annonaceae) against malaria, but its antiprotozoal constituents are not known. Materials and methods The crude 80 ethanol extract from the fruits, leaves, root bark and stem bark and 16 fractions were assessed in vitro for their antiprotozoal activity against Trypanosoma brucei brucei, T. cruzi, Leishmania infantum and the chloroquine and pyrimethamine-resistant K1 strain of Plasmodium falciparum (Pf-K1). Their cytotoxic effects were evaluated against MRC-5 cells. Active constituents were isolated by chromatographic means, identified using spectroscopic methods, and evaluated in the same assays. Results The root bark extract showed the highest activity against P. falciparum K1 (IC50 0.26µg/mL) along with the stem bark alkaloid fraction (IC50 0.27µg/mL). The root bark alkaloid fraction had a pronounced activity against all selected protozoa with IC50 values <1µg/mL. The 90 methanol fractions of the different plant parts showed a pronounced activity against P. falciparum K1, with IC50 values ranging between 0.36µg/mL and 0.69µg/mL. Four constituents were isolated: the triterpenes polycarpol, and dihydropolycarpol, the latter one being reported for the first time from nature, and the alkaloids polyalthenol and N-acetyl-polyveoline. They were active to a various degree against one or more protozoa, mostly accompanied by cytotoxicity. The highest selectivity was observed for N-acetyl-polyveoline against P. falciparum K1 (IC50 2.8µM, selectivity index 10.9). Conclusions These results may explain at least in part the traditional use of this plant species against parasitic diseases such as malaria in DR Congo