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This work concerns the isolation and structure elucidation of compounds obtained from the extract of leaves and stem bark of Combretum fragrans F. Hoffm. Both extracts and some isolated compounds were tested for antiproliferative activity on glioblastoma (U87MG and C6 cells) and prostate (PC-3 cells) cancer cell lines using XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide inner salt) assay. The dichloromethane/methanol (1:1) extract of the leaves led to the isolation of two new compounds such as fragransinate (1) and combretin C (2), alongside five known compounds such as combretin A (3), belamcanidin (4), cirsilineol (5), velutin (6), and a mixture of β-sitosterol-3-O-β-d-glucopyranoside (10a) and stigmasterol-3-O-β-d-glucopyranoside (10b), whereas the methanol extract of the stem bark led to the isolation of three known compounds betulinic acid (7), bellericagenin B (8), and a mixture of β-sitosterol (9a) and stigmasterol (9b). The structure of compounds was elucidated by nuclear magnetic resonance and mass spectrometry data. The methanol extract of the stem bark showed a powerful antiproliferative activity on all tested cells, as well as the extract of leaves which also showed important cytotoxicity effect. Compound (3) showed good antiproliferative activity particularly on U87MG and PC-3 cells, whereas compound (5) exhibits moderated activity. Compounds (2) and (8) were not active on all tested cells.

The aim of this work was to evaluate in vitro antiradical scavenging activity of propolis from Nkambe (North-West, Cameroon). The polyphenol content of the acetone extract was evaluated using the Folin-Ciocalteu reagent as 0.166±0.008 gGAE/100 gRM. Antiradical scavenging activity of hexane and acetone extracts was carried out on DPPH using ascorbic acid as standard. The results showed that the extracts possess antiradical activity with IC50 of 141 μg/mL and 267 μg/mL for acetone and hexane extracts, respectively. The column chromatography separation on silica gel of the hexane fractionyielded compounds 1 to 3. The structures of these compounds were elucidated by NMR and mass spectrometry data as Lupenone (1), a mixture of α and ß-Amyrin (2) and lastly Hexatriacontanoic acid (3) which was described for the first time from propolis.

Objectives: Daniellia oliveri Rolfe is a well-known plant of Fabaceae family whose previous phytochemical and pharmacological studies led to the identification of triterpenoid, phenol, anthraquinone oxalate with antioxidant, antibacterial and antifungal activities. This study aimed to investigate chemical constituents and evaluate the antimicrobial potency of the root of D. oliveri. Methods: The methanol extract of the root barks of D. oliveri was subjected to silica gel chromatographic separation. The structures of the isolated compounds (1 - 9) were determined by analyzing their spectrometric and spectroscopic spectra. Single-crystal-Xray analysis was used to establish the absolute skeletal structure of compound 1. Crude extract, fractions and compounds were investigated against four bacteria vis Pseudomonas aeruginosa 27853, Escherichia coli 5, Staphylococcus aureus 25923 and Streptococcus sp. 9619 and, two yeast vis Candida albicans 14053 and Candida tropicalis 018 using broth microdilution method. Results: The phytochemical prospection of the methanol extract of D. oliveri allowed the isolation of a naturally crystallized diterpenoid type furolabdane: polyalthic acid 1, as well as eight amorphous compounds (2 - 9). Among the tested samples, the crude extract, fractions and compounds selectively showed inhibitory effects against the tested microorganisms with MIC values ranging from 4 to 1024 μg/mL. Fraction D1 and compounds 1, 4, 7, 8 and 9 exhibited the broadest antimicrobial effects among fractions and compounds while D5 and compound 1 showed the best activity with MIC values of 16 and 4 μg/mL respectively against E. coli which appeared to be the most sensitive strain. Conclusion: Polyaltic acid (1) showed the best activity with significant MIC value of 4 μg/mL identical to that of ceftazidine against E. coli. The MIC values of the active compounds 1, 4 and 7 are comparable to those of ceftazidime. Then, these compounds from natural origin, could serve as markers in the standardization of Daniellia plant as phytomedicine. [ABSTRACT FROM AUTHOR]

The cyanobacterial phylum encompasses oxygenic photosynthetic prokaryotes of a great breadth of morphologies and ecologies; they play key roles in global carbon and nitrogen cycles. The chloroplasts of all photosynthetic eukaryotes can trace their ancestry to cyanobacteria. Cyanobacteria also attract considerable interest as platforms for "green" biotechnology and biofuels. To explore the molecular basis of their different phenotypes and biochemical capabilities, we sequenced the genomes of 54 phylogenetically and phenotypically diverse cyanobacterial strains. Comparison of cyanobacterial genomes reveals the molecular basis for many aspects of cyanobacterial ecophysiological diversity, as well as the convergence of complex morphologies without the acquisition of novel proteins. This phylum-wide study highlights the benefits of diversity-driven genome sequencing, identifying more than 21,000 cyanobacterial proteins with no detectable similarity to known proteins, and foregrounds the diversity of light-harvesting proteins and gene clusters for secondary metabolite biosynthesis. Additionally, our results provide insight into the distribution of genes of cyanobacterial origin in eukaryotic nuclear genomes. Moreover, this study doubles both the amount and the phylogenetic diversity of cyanobacterial genome sequence data. Given the exponentially growing number of sequenced genomes, this diversity-driven study demonstrates the perspective gained by comparing disparate yet related genomes in a phylum-wide context and the insights that are gained from it.

Gardenia aqualla a plant of the Rubiaceae family is being used extensively in Africa, particularly in Cameroon as an herbal medicine. Therefore it is necessary to have knowledge of the constituents of the plant of our native species. Thus, the aim of the present study was to investigate chemical constituents of this herbal medicine. Nine compounds, including one alkane, n-Nonacosane (1), two aliphatic alcohols n-heptatriacontanol (2) and n-Docosanol(3), one fatty ester, Heptadecyl heptacosanoate (4), two sugars, D-mannitol (5) and D-mannitol acetate (6), and a mixture of three phytosterols, β-sitosterol (7), stigmasterol (8) and fucosterol (9), have been isolated and purified from the stem barks of Gardenia aqualla Stapf & Hutch. Their structures were elucidated using spectroscopic analyses, including 1D and 2D NMR and ESI-MS. The fatty acid ester, heptadecyl heptacosanoate (4) is reported here for the first time. All the isolated compounds were tested for their antimicrobial activities against four Gram negative bacteria (Salmonella Typhimurium ATCC6539, Pseudomonas aeruginosa ATCC9721, Escherichia coli, and S. Typhi) and four yeasts (Candida albicans ATCC9002, Candida parapsilosis ATCC22019, Candida krusei and C. albicans).

A phytochemical study was carried out on stem bark of Combretum fragrans F. Hoffm., a medicinal plant belonging to the Combretaceae family and used traditionally in the treatment of various ailments. Column chromatography separation on silica gel of the crude methanol extract from stem barks of C. fragrans led to the isolation of a new pentacyclic triterpene acid, with a 3,6-epoxide bridge and trivially named as fragransinic acid (1), along with four known compounds: betulin (2), betulinic acid (3), bellericagenin B (4) and a mixture of β-sitosterol (5) and stigmasterol (6). Structures were elucidated by extensive spectroscopic analyses including 1D and 2D NMR, mass spectrometry as well as by comparison with literature data. The above compounds were isolated for the first time from C. adenogonium. Implications for chemosystematics and traditional medicine were briefly discussed. [ABSTRACT FROM AUTHOR]

Phenolic compounds from propolis have pharmacological properties such as antioxidant, antidiabetic, antiulcer, anticancer. However, they are unstable and oxidize in contact with ultraviolet rays and humidity. In order to limit their oxidation, phenolic compounds need to be protected through a polymeric membrane. The aim of this work is to optimize the encapsulation of phenolic compounds from propolis by complex coacervation using a polymer matrix consisting of gelatin and a Cameroonian tropical gum named Triumfetta cordifolia. A second order regression using Central Composite Design (CCD) was used to determine the optimal conditions of encapsulation as follows: pH (X1) 4.2, gelatin concentration (X2) 54 % and active ingredient concentration (X3) 25 %. The use of Triumfetta cordifolia gum as an anionic polymer led to a considerable encapsulation rate of total polyphenols and flavonoids with the values of 85.75 % and 88.24 % respectively. Concerning the study of the release kinetic of phenolic compounds from propolis, it appeared that the zero-order model better fitted the release in the gastric environment with a high correlation coefficient of R² = 0.99. While in the intestinal environment it was the first-order model which better explained their slowed diffusion into the solvent (R²= 0.97). [ABSTRACT FROM AUTHOR]

Diabetes mellitus is a metabolic disorder which is one of the leading causes of mortality and morbidities in elderly humans. Chronic diabetes can lead to kidney failure, blindness, limb amputation, heart attack and stroke. Physical activity, healthy diets and medications can reduce the incidence of diabetes, so the search for more efficient antidiabetic therapies, most especially from natural products, is a necessity. Herein, extract from roots of the medicinal plant Pterocarpus erinaceus was purified by column chromatography and afforded ten compounds which were characterized by EIMS, HR-FAB-MS, 1D and 2D NMR techniques. Amongst them were, a new trimeric derivative of epicatechin, named 2,3-Epoxyprocyanidin C1 (1); two pentacyclic triterpenoids, friedelin (2) and betulin (3); angolensin (4); flavonoids such as 7-methoxygenistein (5), 7-methoxydaidzein (6), apigenin 7-O-glucoronide (8) and naringenin 7-O-β-D-glucopyranoside (9); and an ellagic acid derivative (10). The extract and compounds were evaluated for their antidiabetic potential by α-amylase and α-glucosidase inhibitory assays. IC50 values of compound 7 (48.1 ± 0.9 µg/mL), compound 8 (48.6 ± 0.1 µg/mL), compound 9 (50.2 ± 0.5 µg/mL) and extract (40.5 ± 0.8 µg/mL) when compared to that of acarbose (26.4 ± 0.3 µg/mL) indicated good α-amylase inhibition. In the α-glucosidase assay, the extract (IC50 = 31.2 ± 0.1 µg/mL), compound 7 (IC50 = 39.5 ± 1.2 µg/mL), compound 8 (IC50 = 40.9 ± 1.3 µg/mL), compound 1 (IC50 = 41.6 ± 1.0 µg/mL), Compound 4 (IC50 = 43.4 ± 0.5 µg/mL), compound 5 (IC50 = 47.6 ± 0.9 µg/mL), compound 6 (IC50 = 46.3 ± 0.2 µg/mL), compound 7 (IC50 = 45.0 ± 0.8 µg/mL), compound 9 (IC50 = 44.8 ± 0.6 µg/mL) and compound 11 (IC50 = 47.5 ± 0.4 µg/mL) all had moderate-to-good inhibitions, compared to acarbose (IC50 = 22.0 ± 0.5 µg/mL). The ability to inhibit α-amylase and α-glucosidase indicates that P. erinaceus and its compounds can lower blood glucose levels by delaying hydrolysis of carbohydrates into sugars, thereby providing a source of natural antidiabetic remedy. [ABSTRACT FROM AUTHOR]