19 research outputs found
Antioxidant Activities and Chemical Constituents of Extracts from Cordyline fruticosa (L.) A. Chev. (Agavaceae) and Eriobotrya japonica (Thunb) Lindl, (Rosaceae)
No full textBackground and Objective: Cordyline fruticosa (Agavaceae) and Eriobotrya japonica (Rosaceae) are two medicinal plants used for the treatment of various diseases such as infections of mammary glands, sore throat and neck pain for the first plant, diabetes, cough, ulcers, protection against oxidative stress and cognitive deficits for the latter. The present study was designed to evaluate the antioxidant activity of the different extracts of these two plants as well as to isolate and identify their chemical constituents. Materials and Methods: The plant extract was prepared by maceration in methanol, compounds were isolated from EtOAc and n-BuOH extracts of the two plants using column chromatography and their structures were determined by means of NMR and MS analysis as well as in comparison with published data. Antioxidant tests (DPPH, ferric reduction antioxidant power and anti-hemolytic) were performed over the MeOH, EtOAc and n-BuOH extracts of the plants. Results: The antioxidant-guided phytochemical investigation of the MeOH extracts of the two plants led to the isolation of twelve compounds identified as: Farrerol 1, quercetin helichrysoside 2, apigenin 8-C-β-D-glucopyranoside 3, isoquercitrin 4 and rutin 5 from C. fruticosa, β-sitosterol 6, catechin 7, oleanolic acid 8, lyoniresinol 9, cinchonain IIb 10, lyoniresinol 2-a-O-β-D-xylopyranoside 11 and β-sitosterol-3-O-β-D-glucopyranoside 12 from E. japonica. Amongst the isolated compounds, the most important antioxidant ones were identified as helichrysoside and rutin from C. fruticosa, catechin, cinchonain IIb, lyoniresinol 2-a-O-β-D-xylopyranoside from E. japonica with EC50 of 8.73, 9.91, 4.11, 3.14 and 10.61 μg mL–1, respectively. Conclusion: Based on the obtained results, it can be concluded that the high ability to scavenge free radicals, reducing power of Fe3+ and hemolysis activity exerted by extracts of C. fruticosa and E. japonica were due to their high content of phenolic compounds, thus the structure-activity relationships of the isolated flavonoids were discussed. The results of this study suggest that the extracts from these two plants could serve as potential source of antioxidant compound
Furan derivatives from Lannea kerstingii
No full textTameko JEM, Chouna JR, Nkeng-Efouet-Alango P, Tapondjou LA, Sewald N. Furan derivatives from Lannea kerstingii. Phytochemistry Letters. 2017;20:282-284.Two new furan derivatives, lannefuran A (1) and lannefuran B (2) were isolated from the stem bark extract of Lannea kerstingii Engl. & K. Krause together with five known compounds, namely: taraxerol, stigmast-4-en-3-one, monoglyceride of hexacosanoic acid, beta-sitosterol and its glucoside. Their structures were determined by means of 1D and 2D NMR, IR, and HR-EI-MS spectra and comparison with the data of known analogues reported in the literature. Lannefuran A (1) exhibited very low antiplasmodial activity against Plasmodium falciparum 3D7
Potential of essential oils from four Cameroonian aromatic plants used in integrated protection of stored products programs: Presentation
No full textThe efficacy of essential oils extracted from fruits of Piper capense and Xylopia parviflora, and roots of Echinops giganteus and Mondia whitei were evaluated against Acanthoscelides obtectus and fungi isolated from bean seeds in laboratory conditions in Cameroon. The essential oils were extracted by water-distillation and their chemical composition identified by Gas Chromatography-Flame Ionization Detection (GC-FID) and Gas Chromatography- Mass Spectrometry (GC-MS). Toxicity assays of essential oils against A. obtectus were carried out by fumigation in which insect pests were exposed fumes of the essential oils, and mortality recorded after 6, 12, and 24 hours. Additionally, the toxicity by contact of the essential oils was evaluated through coating grains with essential oils or impregnating the essential oils onto the filter paper, allowing the insects to physically get in contact with the essential oil, and assessing weevil mortality recorded after 1, 2, 3, and 4 days. The essential oils from P. capense and X. parviflora consisted mainly of hydrocarbon monoterpenes (56.5% and 50.0% respectively), whereas the essential oils from E. giganteus was mostly constituted of sesquiterpenes (94.3%) in which the tricyclic compounds are more abundant. A major compound identified in the essential oil from M. whitei was 2-hydroxy- 4-methoxy-benzaldehyde (81%). The essential oil from X. parviflora was the most effective as contact and fumigant against A. obtectus, causing 100% mortality within 1 day at low lethal concentrations. On the other hand, the essential oil from M. whitei exhibited the best anti-fungal activity. These essential oils could play an important role in pest protection of stored beans and reduce the risks associated with use of synthetic insecticides especially in low income small holder farming systems.The efficacy of essential oils extracted from fruits of Piper capense and Xylopia parviflora, and roots of Echinops giganteus and Mondia whitei were evaluated against Acanthoscelides obtectus and fungi isolated from bean seeds in laboratory conditions in Cameroon. The essential oils were extracted by water-distillation and their chemical composition identified by Gas Chromatography-Flame Ionization Detection (GC-FID) and Gas Chromatography- Mass Spectrometry (GC-MS). Toxicity assays of essential oils against A. obtectus were carried out by fumigation in which insect pests were exposed fumes of the essential oils, and mortality recorded after 6, 12, and 24 hours. Additionally, the toxicity by contact of the essential oils was evaluated through coating grains with essential oils or impregnating the essential oils onto the filter paper, allowing the insects to physically get in contact with the essential oil, and assessing weevil mortality recorded after 1, 2, 3, and 4 days. The essential oils from P. capense and X. parviflora consisted mainly of hydrocarbon monoterpenes (56.5% and 50.0% respectively), whereas the essential oils from E. giganteus was mostly constituted of sesquiterpenes (94.3%) in which the tricyclic compounds are more abundant. A major compound identified in the essential oil from M. whitei was 2-hydroxy- 4-methoxy-benzaldehyde (81%). The essential oil from X. parviflora was the most effective as contact and fumigant against A. obtectus, causing 100% mortality within 1 day at low lethal concentrations. On the other hand, the essential oil from M. whitei exhibited the best anti-fungal activity. These essential oils could play an important role in pest protection of stored beans and reduce the risks associated with use of synthetic insecticides especially in low income small holder farming systems
Propriétés insecticides des huiles essentielles de deux plantes : Exploitation de Clausena anisata et Callistemon viminalis W. dans la lutte contre les bruches de stock
No full textEn Afrique tropicale et subtropicale et plus particulièrement au Cameroun, les légumineuses à grains constituent une source importante de protéines et d’énergie. Le haricot commun et le niébé appartiennent à ce groupe et sont une source d’alimentation de base pour l’homme. Après récolte, ces produits sont généralement stockés dans le but de faire des réserves pour une consommation ultérieure, des semences pour la prochaine saison et aussi dans l’attente d’une période de prix beaucoup plus rémunératrice sur le marché. Malheureusement, ils sont très souvent sujets d'attaque par les insectes de famille des Bruchidae. Ce livre présente quelques généralités sur les huiles essentielles, les effets insecticides des huiles essentielles de deux plantes aromatiques de la région de l'ouest Cameroun, Clausena anisata (Wild). et Callistemon viminalis W. à l'égard de deux bruches à savoir Acanthoscelides obtectus (bruche du haricot commun) et C allosobruchus maculatus (bruche du niébé). L’optimisation de la rémanence de l’activité insecticide de ces huiles y est également présentée à travers l’utilisation d’une argile smectite locale de nature adsorbante comme support de ces huiles
Cycloartane glycosides from leaves of Oxyanthus pallidus
No full textInternational audienceFrom the MeOH extract of leaves of Oxyanthus pallidus, three cycloartane glycosides, named pallidiosides A–C, were isolated together with two known compounds, oleanolic acid and 3-O-β-d-glucopyranosyl-β-sitosterol. The structures of pallidiosides A–C were assigned on the basis of spectral studies and comparison with published literature data. The known compounds were identified by means of Co TLC and confirmed by their physical constant
Insecticidal effects of the powdery formulation based on clay and essential oil from the leaves of Clausena anisata (Willd.) J. D. Hook ex. Benth. (Rutaceae) against Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae)
No full textThe bioefficacies of essential oil and aromatized clay powder based on the mixture of clay and essential oil extracted from Clausena anisata were evaluated for their insecticidal activities and their effects on progeny production of Acanthoscelides obtectus. Contact toxicity assayed by coating on bean grains showed that these chemicals caused significant mortality of the test insect. Beetle mortality was dose dependant and after 2-day exposure the aromatized clay powder was more toxic (LD50 = 0.069 mu l/g grain) than the pure essential oil (LD50 = 0.081 mu l/g grain). There was, however, a highly significant loss of toxicity after 24 and 36 h following treatment with essential oil and aromatized powder, respectively. Both aromatized clay powder and pure essential oil considerably reduced the F-1 progeny insect production. The essential oil evoked moderated repellent action and high fumigant toxicity (LC50 = 0.093 mu l/cm(3)) against adults of A. obtectus. These results suggest that the clay powder could be used to stabilize the essential oil to increase its efficacy for use as an alternative to synthetic insecticides
ChemInform Abstract: Bafoudiosbulbins F (Ia) and G (Ib), Further Clerodane Diterpenoids from Dioscorea bulbifera L. var sativa and Revised Structure (III) of Bafoudiosbulbin B (II).
No full text23-Hydroxyursolic Acid Isolated from the Stem Bark of <i>Cussonia bancoensis</i> Induces Apoptosis through Fas/Caspase-8-Dependent Pathway in HL-60 Human Promyelocytic Leukemia Cells
No full textThe natural product 23-hydroxyursolic acid (23-HUA) is a derivative of ursolic acid, which is known to induce cancer cell apoptosis. However, apoptotic effects and mechanisms of 23-HUA have not been well characterized yet. Herein, we investigated the molecular mechanisms of 23-HUA-induced apoptosis in HL-60 human promyelocytic leukemia cells. 23-HUA-treated HL-60 cells showed apoptotic features including internucleosomal DNA condensation and fragmentation as well as externalization of phosphatidylserine residues. 23-HUA induced a series of mitochondrial events including disruption of mitochondrial membrane potential (ΔΨm), cytochrome c and Smac/DIABLO release and loss of balance between pro-apoptotic and anti-apoptotic Bcl-2 proteins in HL-60 cells. In addition, 23-HUA activated caspase-8, caspase-9 and caspase-3. Pretreatment with a broad caspase inhibitor (z-VAD-fmk), a caspase-3 inhibitor (z-DEVD-fmk), and a caspase-8 inhibitor (z-IETD-fmk) significantly attenuated 23-HUA-induced DNA fragmentation. After 23-HUA-induced apoptosis, proteins expression levels of FasL, Fas and FADD constituting the death-inducing signaling complex (DISC) were upregulated in HL-60 cells. Moreover, transfection with Fas or FADD siRNA significantly blocked 23-HUA-induced DNA fragmentation and caspases activation. Taken together, these findings indicate that 23-HUA induces apoptosis in HL-60 human promyelocytic leukemia cells through formation of DISC and caspase-8 activation leading to loss of ΔΨm and caspase-3 activation
Antimicrobial and antioxidant flavonoids from the leaves of Oncoba spinosa Forssk. (Salicaceae)
No full text
