Etude de l’Origine et de L’Identité de quelques Types d’Huiles Végétales Raffinées Commercialisées à Douala/Cameroun

Les huiles végétales raffinées sont des sources d’énergie, d’acides gras essentiels, d’antioxydants et de vitamines liposolubles. Elles permettent de lutter contre la malnutrition et le vieillissement cellulaire. Les mauvaises conditions d’extraction, de raffinage, de conservation et de stockage peuvent altérer l’identité et la qualité de ces produits. L’objectif de ce travail était d’évaluer l’origine et l’identité de 56 échantillons d’huiles végétales commercialisées à Douala. Pour ce faire nous avons étudié la représentativité des variétés d’huiles sur le marché et leur origine, l’indice d’iode, l’indice de saponification et la conformité de l’étiquetage. Les résultats montrent que le marché des huiles végétales raffinées est dominé par les produits importés avec 57,2% de part de marché. Moins de 30% des échantillons analysés étaient conformes à la norme camerounaise NC 04 :2000-20sur l’étiquetage des denrées alimentaires pré emballées. Aucun échantillon analysé n’a eu un indice d’iode, ni de saponification, conforme à la norme du Codex Alimentarius et la norme camerounaise NC 77 : 2002-03, REV.1. de 2011 portant sur les huiles végétales enrichies en vitamine A. Les huiles raffinées analysées auraient été adultérées ou auraient subies une altération avancée par le phénomène d’auto oxydation catalysé par la chaleur. Elles ne seraient pas des corps gras purs. Cette étude suggère que des efforts considérables doivent être entrepris en plus des acquis dont dispose le Cameroun dans le domaine du contrôle de qualité des denrées alimentaires.Mots clés: Huiles végétales, Contrôle Qualité, Norme, Conformité d’étiquetageEnglish AbstractRefined vegetable oils are sources of energy, essential fatty acids, antioxidants and fat-soluble vitamins. They help fight against malnutrition and cellular aging. Poor extraction, refining, storage and storageconditions can alter the identity and quality of these products. The objective of this work was to evaluate the origin and identity of 56 vegetable oil samples marketed in Douala. We studied the representativenessof the different oil varieties from the market and their origin, the iodine index, the saponification index and the conformity of the labeling. The results show that the market for refined vegetable oils is dominated by imported products with a 57.2% market share. Less than 30% of the samples analyzed complied with the Cameroonian standard NC 04: 2000-20 on the labeling of prepackaged foods. No samples analyzed had an iodine or saponification index in accordance with the Codex Alimentarius standard and the Cameroonian standard NC 77: 2002-03, REV.1. Of 2011 on vegetable oils fortified with vitamin A. The refined oils analyzed were adulterated or might have undergone advanced alteration by the phenomenon of auto-oxidation catalyzed by heat. These oils are therefore not really pure fats. This study suggests that considerable efforts must be made in addition to Cameroon’s achievements in the field of quality control of foodstuffs.Keywords: Vegetable Oils, Quality Control, Norms, Labeling Complianc

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Improving Farmers’ Revenue in Crop Rotation Systems with Plot Adjacency Constraints in Organic Farms with Nutrient Amendments

The search for sustainable agriculture is leading many economies to turn to crop rotation systems and to abandon monoculture systems which generally require increased use of pesticides and synthetic fertilizers. But the optimization of crop rotation remains a challenge, especially when considering organic farming. This work tackles the optimization of crop rotation in traditional organic farms with plot adjacency constraints and nutrient amendments. In the present configuration, each farmer owns a certain quantity of rudimentary equipment and a number of workers, all considered as resources. Farms are subdivided into plots and each plot allows only one crop at a given period. At a given interval of time, each plot receives a certain quantity of nutrient. The generated rotations are of fixed durations for all plots and the objective is to maximize farmers’ income. A linear programming approach is used to determine the solution of the proposed farming model. Three levels of constraints are combined in the linear program to generate realistic rotations: (i) biophysical constraints including crop succession and plot adjacency; (ii) structural constraints including budget and resources; (iii) organizational constraints such as nutrient amendment and market demand. To evaluate the performance of the model, scenarios based on real-world data has been defined and solved using free solvers. The solutions obtained indicate that all the constrains are satisfied. In addition, farmers’ revenue is improved, reaching a stationary position when the quantity of available resources is equal or greater than the quantity of required resources. Finally, Cbc solver is faster than GLPK solver; and it provides solutions on larger instances where GLPK does not

A rotameric tryptamide alkaloid from the roots of Vepris lecomteana (Pierre) Cheek & T. Heller (Rutaceae)

Kouam ADK, Kenmogne SB, Lobe JS, et al. A rotameric tryptamide alkaloid from the roots of Vepris lecomteana (Pierre) Cheek & T. Heller (Rutaceae). FITOTERAPIA. 2019;135:9-14.A rotameric tryptamide alkaloid (1a-1b) was isolated from the methanolic extract of the roots of Vepris lecomteana together with the known compounds anhydroevoxine (2), lecomtequinoline C (3), evoxine (4), N-methylflindersine (5), evoxanthine (6), hesperidin, lupeol, beta-sitosterol and stigmasterol. The previously not reported 7-(3-anilino-2-hydroxyprenyloxy)-8-methoxydictamine (2a) was obtained by opening the epoxide of anhydroevoxine (2). The structures of above compounds were determined by comprehensive spectroscopic analyses of 1D and 2D NMR, EI-/ESI-MS, X-ray crystallography and comparison with the reported data. At room temperature, H-1 and C-13 NMR spectra show two rotamers (1a and 1b) with integrated intensities of 2/3, whereas at around 60 degrees C, only the 1b conformer was observed. Furthermore, the crystal structure of 1 was determined by the direct method of single crystal X-ray diffraction. The suggested biosynthesis for the formation of the new rotameric tryptamide alkaloid 1 is presented. Some of the isolated compounds (1, 2 and 2a) were tested in vitro against bacteria, resulting in weak for (1 and 2) to moderate activity for (2a) against Micrococcus Mulls and Escherichia coli with MIC values of 15.3 and 15.3 mu g/mL, respectively

Antimicrobial Furoquinoline Alkaloids from Vepris lecomteana (Pierre) Cheek & T. Heller (Rutaceae)

Three new prenylated furoquinoline alkaloids named lecomtequinoline A (1), B (2), and C (3), together with the known compounds anhydroevoxine (4), evoxine (5), dictamnine (6), N-methylflindersine (7), evoxanthine (8), hesperidin, lupeol, β-sitosterol, stigmasterol, β-sitosterol-3-O-β-d-glucopyranoside, stearic acid, and myristyl alcohol, were isolated by bioassay-guided fractionation of the methanolic extracts of leaves and stem of Vepris lecomteana. The structures of compounds were determined by spectroscopic methods (NMR, MS, UV, and IR) and by comparison with previously reported data. Crude extracts of leaves and stem displayed high antimicrobial activity, with Minimum Inhibitory Concentration (MIC) (values of 10.1–16.5 and 10.2–20.5 µg/mL, respectively, against Escherichia coli, Bacillus subtilis, Pseudomonas agarici, Micrococcus luteus, and Staphylococcus warneri, while compounds 1–6 showed values ranging from 11.1 to 18.7 µg/mL or were inactive, suggesting synergistic effect. The extracts may find application in crude drug preparations in Western Africa where Vepris lecomteana is endemic, subject to negative toxicity results in vivo

A New Aromatic Amide from the Roots of Zanthoxylum tessmannii (Rutaceae).

Kenmoe Djeukeu C, Kouam Kenmogne A, Guy Blaise Azebaze A, et al. A New Aromatic Amide from the Roots of Zanthoxylum tessmannii (Rutaceae). Chemistry & biodiversity. 2019;16(4):e1800590.Phytochemical investigation of the methanolic extract of the roots of Zanthoxylum tessmannii Zepernick and Timler (Rutaceae) led to the isolation and characterization of one new aromatic amide named tessmamide (1) along with twelve known compounds, N-benzoyltyramine methyl ether (2), 7,8,9-trimethoxycoumarin (3), 7,8-dimethoxycoumarin (4), integrifoliodiol (5), robustin (6), skimmianine (7), lupeol (8), lupenone (9), a mixture of stigmasterol and beta-sitosterol, and a mixture of their glucosides. The structures of all compounds were determined by comprehensive spectroscopic analyses (1D- and 2D-NMR, EI-MS, and ESI-MS) and comparison with known analogs. The determination of the radical scavenging activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay gave moderate antioxidant values for the crude extracts of the roots of Zanthoxylum tessmannii (IC50 0.8 mg/mL), tessmamide (1; IC50 31.8 mum), and 7,8,9-trimethoxycoumarin (3; IC50 29.3 mum), compared to the standard ascorbic acid (IC50 11.6 mum). © 2019 Wiley-VHCA AG, Zurich, Switzerland

Mimonoside D: a new triterpenoid saponin from Sauvalle (Fabaceae).

A new triterpenoid saponin (Mimonoside D: 3-O-α-L-arabinopyranosyl-3β-hydroxyolean-12-en-28-oic acid 28-O-β-D-xylopyranosyl-(1→2)-β-D- glucopyranoside ester (1)) was isolated from the aerial parts of Mimosa diplotricha Sauvalle together with nine known compounds: 7,4'-dihydroxyflavone (2), kaempferol (3), lupeol (4), betulinic acid (5), β-sitosterol (6), β-sitosterol-3-O-β-D-glucopyranoside (7), lutein (8), 5,2'-dihydroxy-7,4',5'-trimethoxyflavone (9) and vitexin (10). Their structures were elucidated on the basis of spectroscopic (1 D and 2 D nuclear magnetic resonance) and high-resolution mass spectrometric data as well as by comparison of their spectral data with those of related compounds. Compounds 2, 7 and 8 had already been isolated from M. diplotricha, while compounds 3, 4, 5 and 6 have been isolated from other Mimosa species. Compound 2 moderately inhibited Proteus mirabilis (MIC = 32 µg/mL), weakly inhibited Pseudomonas aeruginosa (MIC = 64 µg/mL) and very weakly inhibited Staphylococcus aureus (MIC = 128 µg/mL) and Enterococus faecalis (MIC = 128 µg/mL)

Coumarinolignoid and Indole Alkaloids from the Roots of the Hybrid Plant Citrus × paradisi Macfad (Rutaceae)

A phytochemical investigation of the roots of Citrus × paradisi Macfad. (Rutaceae) led to the isolation of two new compounds, namely 1-formyl-5-hydroxy-N-methylindolin-1-ium (1) and decyloxycleomiscosin D (2), along with ten known compounds: 1,1-dimethylpyrrolidin-1-ium-2-carboxylate (3), furan-2,3-diol (4), 5-methoxyseselin (5), umbelliferone (6), scopoletin (7), citracridone I (8), citracridone II (9), citracridone III (10), limonin (11) and lupeol (12). The structures were determined through the comprehensive spectroscopic analysis of 1D and 2D NMR and EI- and ESI-MS, as well as a comparison with the published data. Notably, compounds 3 and 4 from the genus Citrus are reported here for the first time. In addition, the MeOH extract of the roots and compounds 1–7 were screened against the human adenocarcinoma alveolar basal epithelial cell line A549 and the Caucasian prostate adenocarcinoma cell line PC3 using the MTT assay. While the extract showed significant activity, with IC50 values of 35.2 and 38.1 µg/mL, respectively, compounds 1–7 showed weak activity, with IC50 values of 99.2 to 250.2 µM and 99.5 to 192.7 µM, respectively

Chemical Constituents of the Stem Bark of the Hybrid Plant Citrus * paradisi Macfad. (Rutaceae)

Essombe Malolo F-A, Bellier Tabekoueng G, Dongmo Tekapi Tsopgni W, et al. Chemical Constituents of the Stem Bark of the Hybrid Plant Citrus * paradisi Macfad. (Rutaceae). Chemistry & biodiversity. 2022: e202101033.The stem bark of Citrus * paradisi Macfad. (Rutaceae) gave (23S)-isolimonexic acid (1), limonin (2), citracridone II (3), citpressine II (4), citpressine I (5), grandisine (6), 2-hydroxynoracronycine (7), citracridone I (8), 5-methoxyseselin (9), umbelliferone (10), scopoletin (11), naringenin (12), apigenin (13), friedelin (14), agrostophyllinone (15) and stigmasterol-3-O-beta-D-glucopyranoside (16). The structures of the compounds were determined using NMR and MS spectroscopic data, and by comparison with published data. The relative configuration of 1 was proposed as (23S)-isolimonexic acid using NOE studies. Hydrogenation reaction of compound 3 led to the new derivative 3',4'-dihydrocitracridone II (3a). Cytotoxicity activities against the human adenocarcinoma alveolar basal epithelial cell lines A549 and the Caucasian prostate adenocarcinoma cell lines PC3, using the MTT assays showed that the methanol crude extract was significant with IC50 values of 30.1 and 31.7 mug/mL, respectively, with the positive control, doxorubicin giving an IC50 of 0.9 muM. In addition, compounds 3, 7 and 8 gave moderate cytotoxic activities with IC50 values of 33.1, 31.2 and 32.5 muM for A549 cells and 35.7, 33.8 and 34.9 muM for PC3 cells, respectively. The hydrogenated 3a was less active than 3, suggesting that the presence of the double bond in pyrans is important for structure-activity relationship. © 2022 Wiley-VHCA AG, Zurich, Switzerland

First report of compounds from an Ancistrocarpus species: Triterpenoids from A. densispinosus Oliv. (Malvaceae).

Peyeino JH, Djomkam HLM, Kenmogne SB, et al. First report of compounds from an Ancistrocarpus species: Triterpenoids from A. densispinosus Oliv. (Malvaceae). Natural product research. 2020.The stem bark of Ancistrocarpus densispinosus Oliv. exhibited triterpenoids, including the rare fernane-type, fern-9(11)-ene-2alpha,3beta-diol (1) a possible chemotaxonomically distinct biomolecule for the genus. Other triterpenoids that were isolated from this plant include the ursane-type ursolic acid (2) and corosolic acid (3), friedelane-type friedelin (4) and canophyllol (5), lupane-type lupeol (6), betulin (7), betulinic acid (8) and hennadiol (9), oleanoic acid (10), maslinic acid (11) and taraxerol (12) and three sterols. This is the first report of the chemistry of a plant of the Ancistrocarpus. The structures of the compounds were elucidated based on their NMR, IR and MS techniques and by comparisons of their experimental data with those reported. The twelve triterpenoids 1-12 were found to be inactive against five bacterial strains Escherichia coli, Bacillus subtilis, Pseudomonas agarici, Micrococcus luteus and Staphylococcus warneri; inactive against KB-3-1 cervix carcinoma cancer cell line and inactive as antioxidants in the DPPH assay