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The orange-yellow and colorless essential oils with respective yields of 1.54% and 3.59% were extracted from the dry leaves of Cymbopogoncitratus (DC.) Stapf and Eucalyptus citriodora Hook. collected south of Brazzaville. Analysis by gas chromatography (GC) and by gas chromatography coupled with mass spectrometry (GC/MS) allowed the identification of fifteen (15) and eight (8) constituents representing (96.25%) and (98.46%) of total essential oils respectively. Cymbopogoncitratus oil consists mainly of geranial (51.99%) and neral (32.94%), two geometric isomers constituting citral which occupies a rate of 84.93%. While citronellal with a high level of (80.72%) and citronellol (10.48%) are the major compounds of the essential oil of Eucalyptus citriodora. Geranial (citral a) and citronellal 2,4-dinitrophenylhydrazones were hemi-synthesized by a simple, easy method, respectively from essential oils of Cymbopogoncitratus and Eucalyptus citriodora with respective conversion rate (yields) of 20%. and 37%, in a short time (three to five minutes). Analysis of geranial and citronellal 2,4-dinitrophenylhydrazones by UV-visible spectrophotometry showed maximum absorption wavelengths of 390 nm and 370 nm respectively. The UV-visible spectrophotometric method employed for the determination of these hydrazones is convenient, fast and simple. The hemi-synthesized hydrazones could be useful in the pharmaceutical industry, in perfumery, cosmetic and in biomedicine.

Background: Despite advances in hygiene and preventive medicine, parasitic diseases, particularly digestive parasitosis, remain a public health problem in tropical countries. Elaborate the ethnobotanical survey carried out in Brazzaville - Congo, 21 plants (divided into 20 families, 20 genera) were identified, among them 9 were selected for this study. These were: Ageratum conyzoides (L.) L., Rauvolfia mannii Stapf, Aloe buettneri A. Berger, Garcinia kola Heckel, Piper guineense Schumach & Thonn., Aframomum alboviolaceum (Ridl.) K. Schum., Plagiostyles africana (Müll .Arg.) Prain, Morinda lucida Benth, Cogniauxia podoleana Baill. Materials and Methods: The in vitro evaluation of the anthelmintic activity of the aqueous extracts of these 9 plants was determined at concentrations of 10, 25 and 50 mg/mL against Lumbricus terrestris used as animal support in comparison to the Mebendazole (20 mg/mL). The phytochemical screening realized by TLC to detect phytochemical families in plant, also, the antioxidant potential with DPPH radical was determined by UV-Visible spectrophometry in comparison to the Vitamin C. Results: Thus, P. guineense, A. conyzoides and A. alboviolaceum are those which presented significant vermicidal effect, after Mebendazole. Phytochemical screening into TLC revealed the co-presence of alkaloids, coumarins, flavonoids, tannins, sterols and terpenes.The antioxidant potential of the aqueous extracts of these different plants in comparison to vitamin C, has shown that the species A. Buettineri and A. alboviolaceum presented the best potential compared to 7 other species studied, with the concentration needed to reduce 50% of the DPPH radical (CR50) respectively 0.096 mg/mL for A. Buettineri, 0.098 mg/mL for A. alboviolaceum Berger and 0.015 mg/mL for vitamin C. Conclusion: There is modern drugs against intestinal worms, it is necessary to identify the plants with anthelmintic activity, to determine phytochemical compounds that would be responsible for their use by traditional healers to treat the intestinal parasitosis.

The purpose of this work is to evaluate antiprolifertive and DPPH radical scavenging activities of aqueous extracts from Morinda lucida Smith, Klainedoxa gabonensis Pierre ex Engl, Tephrosia vogelii Hook f and Nauclea latifolia Sm. The antiproliferative activity of the aqueous extract of each of the four species was evaluated in vitro on a cancer cell line (U87-MG) and a normal cell line (Hek-293) using the MTT assay. The antiradicalar activity was evaluated by measuring the scavenger capacity of the DPPH radical. Phytochemical analyzes of the extract were performed by thin layer chromatography and HPLC-PDA. The aqueous extracts of Klainedoxa gabonenis and Tephrosia vogelii showed antiproliferative activity against U87-MG cancer cells with IC50 values below 90 μg / ml. The aqueous extract of Klainedoxa gabonenis also showed remarkable antiradical activity (IC50 = 4± 0,73 μg/ml). In addition, the treatment of U87-MG cancer cells by both the aqueous extract of Klainedoxa gabonensis (100 μg / ml) and by an MEK protein inhibitor (1 μM) causes a total suppression of U87-cell proliferation. MG (glioblastoma). HPLC-PDA analysis of the aqueous extract Klainedoxa gabonenis showed the presence of gallic acid compounds (41.9%) and Quercetin (2.17%).: Our study identified two medicinal plants with antiproliferative properties among the four Congolese herbal medicines evaluated, one with both anti-proliferative and antiradical properties. Le but de ce travail est d’evaluer les proprietes antiproliferative et antiradicalaire des extraits aqueux de quatre plantes medicinales congolaises dont Morinda lucida, Klainedoxa gabonensis, Tephrosia vogelii et Nauclea latifolia. L’activite antiproliferative de l’extrait aqueux de chacune des quatre especes a ete evaluee in vitro sur une lignee cellulaire cancereuse (U87-MG) et une lignee cellulaire normale (Hek-293) en utilisant le test MTT. L’activite antiradicalaire a ete evaluee en mesurant la capacite de piegeage du radical DPPH. Des analyses phytochimiques des extraits ont ete realisees par chromatographie sur couche mince et par HPLC-PDA. Les extraits aqueux de Klainedoxa gabonenis et de Tephrosia vogelii ont montre une activite antiproliferative contre les cellules cancereuses U87-MG avec des valeurs de CI50 inferieures a 90 µg/ml. L’extrait aqueux de Klainedoxa gabonenis a montre egalement une activite antiradicalaire remarquable (CI50 = 4 ± 0,73 µg/ml) .En plus, le traitement des cellules cancereuses U87-MG a la fois par l’extrait aqueux de Klainedoxa gabonensis (100 µg/ml) et par un inhibiteur de la proteine MEK (1µM) provoque une suppression totale de la proliferation des cellules U87-MG (glioblastome). L’analyse en HPLC–PDA de l’extrait aqueux Klainedoxa gabonenis a montre la presence des composes de type acide gallique (41, 9 %) et quercetine (2,17 %). Notre etude a permis d’identifier deux plantes medicinales aux proprietes antiproliferatives parmi les quatre plantes medicinales congolaises evaluees dont une possedant a la fois les proprietes antiproliferative et antiradicalaire.

The chemical composition of the essential oils from leaves, stems bark, roots bark, epicarp and mesocarp of Annona senegalensis Pers., oulotricha Le Thomas subspecies (Annonaceae), growing in Brazzaville (Congo), were analyzed by CG and CG-MS. These oils essentially contain sesquiterpenic compounds (58.3 - 97.7%), dominated by oxygenated sesquiterpenes (21.8 - 88.3%), with elemol (13.2 - 35.0%), β and γ-eudesmols (3.7 - 58.3%) as characteristic components. The essential oils from roots and stems bark is distinguished by its high content in diterpenes (17.1 and 11.9% of the total), while the seeds presents a significant amounts of monoterpene hydrocarbons (25.8%) with α-pinene (6.2%) and β-phellandrene (11.5%) as major components accompanied by two oxygenated monoterpenes: bornyle acetate (4.5%) and smallest of 1,8-cineole. However, in the epicarp oil, the presence of about 5.8% of oxygenated monoterpenes as terpinen-4-ol and bornyle acetate in comparable rates (1.7%) was noted. The mesocarp oil is exclusively rich in aliphatic fatty acids (35.8%) which is absent in the other organs, but represented by lauric acid (18.0%), hexadecanoic acid (8.6%), myristic acid (7.2%) and oleic acid (2.0%). Results were compared with same species collected in the democratic republic of Congo and in Cameroon essentially dominated by monoterpenes (84.2 and 87.6%).