One benzophenone, 4′-hydroxy-2,4,6-trimethoxybenzophenone (1) was isolated from the liana and leaves of Salacia nitida (Benth.) N.E.Br., together with n-hexacosane (2), 29-hydroxyfriedelane (3), 3β-friedelinol (4), n-hexacosan-1-ol (5), n-octacosan-1-ol (6), mangiferin (7), β-sitosterol-3-O-β-D-glucopyranoside (8), friedelin (9), 30-hydroxyfriedelin (10), salaspermic acid (11), 22β-epi-maytenfolic acid (12), orthosphenic acid (13), maltose (14), D-mannitol (15), cangoronine (16), 7-hydroxyfriedelane-1,3-dione (17), tingenone (18), pristimerin (19), α-amyrin acetate (20), β-sitosterol (21) and stigmasterol (22), 21-hydroxyfriedelan-3-one (23), abruslactone A (24), and 2α-hydroxypopulnonic acid (25). The structures of the isolated compounds were established by means of spectroscopic analysis. In addition, the structure of (1) was confirmed by its X-ray diffraction. Compounds (1), (7), (10)-(11), (13), (16)-(19) and (25) were evaluated for their antimicrobial activities. Compound (18) showed a significant activity against Staphylococcus aureus (MIC = 23.8 µM) while compounds (11) and (19) exhibited moderate inhibiting effect against Staphylococcus aureus (MIC = 53.8 µM) and Candida glabrata (MIC = 105.9 µM), respectively. Manuscript profile

One new coumarinolignan, cleomiscosin F (1) along with ten known compounds namely 3,4-secotirucalla-4(28),7,24-trien-21-hydroxy-21,23-epoxy-3-oic acid (2), 3,4-secotirucalla-4(28),7,24-trien-3,21-dioic acid (3),ceramid A (4),ceramid B (5), mayombensin (6),aridanin (7), stigmasterol and β-sitosterol and their glucosides were isolated from the seeds and roots of Leplaea mayombensis (Meliaceae).Thestructures of the compounds were elucidated based on the interpretation of their spectroscopic data. Some of the isolated compounds (3, 4 and 5) were tested in vitro against bacteria strains Escherichia coli, Bacillus subtilis, Pseudomonas agarici, and Micrococcus luteus. Compound 3 displayed good activity against Bacillus subtilis, Micrococcus luteus, and Pseudomonas agarici with MIC values of 1.7, 2.3 and 9.8µM, respectively; while compound 4 showed significant activity against Micrococcus luteus with MIC value of 11.9µM. Manuscript profile

The MeOH extract of the ripe fruits of Nauclea latifolia Sm. (Rubiaceae) showed potent antileishmanial activity in vitro during preliminary screening (IC50 = 2.20 µg/mL) against Leishmania donovani 1S (MHOM/SD/62/1S) promastigotes. Three of the four fractions of this extract showed moderate to good activities (7.06 ≤ IC50 ≤ 91.21 µg/mL) on the same strain. The purification of the fractions through CC yielded fifteen compounds whose structures were established based on their MS and NMR data. All the isolated compounds were assessed for their antileishmanial activity against L. donovani and for their cytotoxicity towards Raw 264.7 macrophage cells. 2,6-Dimethoxybenzoquinone (1) and hederagenin (6) showed good antileishmanial activity with IC50 values of 9.94 and 19.3 µM, respectively. Compound 1 was not selective, while compound 6 displayed a good selectivity towards raw 264.7 macrophage cells (SI > 7.82). These results indicate that the extract from N. latifolia fruits could be considered as a source of leishmaniacidal agents. Manuscript profile

Eighty-nine essential oil analyses carried out on Cameroonian plant material by gas chromatography are reviewed, and structures of sixty one main oil compounds are presented. Plant samples had been collected all over the rainforest area and further northwards, covering forty plant species belonging to ten families. For these plants, common names, traditional use as well as bioactivity and toxicity of their essential oils in vitro and in vivo are compiled. Data show that oils from leaves, bark, roots, fruit, rhizome or seeds display their own one to four main essential oil components. Each of them contributing more than 10% to over 90% of the oil´s volume, which sums up to species-unique essential oil fingerprints and decreasing similarity of these fingerprints with increasing phylogenetic distance between species. This review article shows that the environmental factor include, temperature, rainfall (Littoral region), humidity (Center, South, East and West regions) and solar radiation (Adamaoua, North and Far-north regions) as well as the soil nutrients influence the secondary metabolite composition of the plants. Bioassays valorized traditional use of a good number of oils, for example against the dermatophytic fungus Trichophyton rubrum being twice as effective as amphothericin B®; against the chloroquine resistant Plasmodium falciparum; against cancer cell lines; and against a variety of human pathogen bacteria, being up to ten times as effective as ciproxin®, lidaprim®, tetracycline hydrochloride® and lidaprim®. Importantly, in an experiment employing the stored product beetle Callosobruchus maculatus, the leaf oil of Lippia adoensis (Verbenaceae) indicated neurotoxicity, so that preparations should be applied with care. Follow up work may focus on bioassays with commercial pure compounds, with the goal to improve effectivity and doses calculation for traditional essential oil medicines and agricultural products. Manuscript profile

Forty traditional medicinal plants from the Cameroonian rain forest belonging to twelve families are reviewed related to botanical description, taxonomy, common names, traditional use, essential oil composition as well as bioactivity and toxicity of their essential oils. A correlation is drawn between traditional use and bioactivity in vitro/in vivo, and structures of seventy-three main oil ingredients are given. Collected data indicate that plant essential oils unfold their biological activity related to functional groups of major and minor compounds, in a complex, fine-tuned interaction, modulated by environmental factors like the vegetation cycle of the plant, the altitude and the presence or absence of plant pathogen microbes, certain crop weevils as well as nematodes, varying with climatic seasons. Comparison of traditional use with laboratory results indicates effectivity of a good number of essential oils received from various plant parts, like leaves, bark, fruit, roots and rhizomes against Plasmodium falciparum, food borne microbes, dermatophytes, the malaria vector Anopheles gambiae, cancer cell lines, river blindness as well as plant pathogen weevils and fungi. However, toxicological studies are needed before any recommendation for application can be given. Importantly, leaf and fruit oil of Cupressus lusitanica (Cupressaceae) displayed strong acute toxicity in animal model, and the bark oil of Cinnamomum verum (Lauraceae) showed high toxicity in a normal cell line, so that preparations should be applied with care. Preformulation and formulation studies will be needed to develop a range of suitable dosage forms to introduce optimized pharmaceuticals (high active, low toxic) as replacement of current crude plant essential oil preparations in Cameroon and other Subsaharan countries. Manuscript profile