36 research outputs found
UV-Vis spectrophotometry and chemometrics as tools for recognition of the biochemical profiles of organic banana peels (Musa sp.) according to the seasonality in southern Brazil
Banana (Musa sp.) has received wide interest in popular and scientific medicine because of its rich composition in bioactive metabolites, e.g., phenolic compounds, found in interesting concentrations in its peel. Banana peel is a residue that is under-exploited by the industry. Thus, with the intention to give a destination to this by-product towards health care or cosmetics industries, we evaluated its aqueous extract (AE) as a source of bioactive phenolic compounds, aiming at to apply them in future studies of biological activities. For that, in this study samples of banana peels were chemically profiled throughout the year to identify the best harvest time of those biomasses regarding their phenolic composition. In this sense, we used additional information on the chemical heterogeneity of the samples determined by the seasoning, through a set of analytical and climatic data to elaborate chemometric models, supported by bioinformatics tools. Through PCA and HCA analyzes, it was detected that low temperatures; normally observed in winter; strongly modulate the banana metabolism, leading to increased amounts of phenolic compounds, and improving the antioxidant activity of the banana peel AE. The samples collected during the months of winter showed a similar profile and a relatively high concentration of phenolic compounds with potential for future studies of biological activities.CAPES -Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(407323/2013-9)info:eu-repo/semantics/publishedVersio
Compounds from <em>Terminalia mantaly</em> L. (Combretaceae) Stem Bark Exhibit Potent Inhibition against some Pathogenic Yeasts and Enzymes of Metabolic Significance<strong></strong>
Tchuenmogne MAT, Ngouana TK, Gohlke S, et al. Compounds from <em>Terminalia mantaly</em> L. (Combretaceae) Stem Bark Exhibit Potent Inhibition against some Pathogenic Yeasts and Enzymes of Metabolic Significance<strong></strong>. Preprints. 2016.The chemical investigation of the anti-yeast methanol extract from the stem bark of Terminalia mantaly led to the isolation of seven compounds: 3-O-methyl-4-O-&alpha;-rhamnopyranoside ellagic acid (1), 3-O-mehylellagic acid (2), arjungenin or 2,3,19,23-tetrahydroxyolean-12-en-28-o&iuml;c acid (3), arjunglucoside or 2,3,19,23-tetrahydroxyolean-12-en-28-o&iuml;c acid glucopyranoside (4), 2&alpha;,3&alpha;,24-trihydroxyolean-11,13(18)-dien-28-o&iuml;c acid (5), stigmasterol (6), stigmasterol 3-O-&beta;-D-glucopyranoside (7). Their structures were established by means of spectroscopic analysis and comparison with published data. Compounds 1-5 were tested in vitro for activity against three pathogenic yeast isolates, Candida albicans, Candida parapsilosis and Candida krusei. The activity of compounds 1, 2 and 4 were comparable to that of the reference compound fluconazole (MIC values below 32 &micro;g/ml) against the three tested yeast isolates. They were also tested for inhibitory properties against four enzymes of metabolic significance: Glucose-6-Phosphate Deshydrogenase (G6PD), human erythrocyte Carbonic anhydrase I and II (hCA I and hCA II), Glutathione S-transferase (GST). Compound 4 showed highly potent inhibitory property against the four tested enzymes with overall IC50 values below 4 &micro;M and inhibitory constant (Ki) &lt;3 &micro;M.</jats:p
Antiplasmodial and cytotoxic activities of flavonoids and arylbenzofuran derivatives from Morus mesozygia
Morus mesozygia Stapf (Moraceae) is a plant found in many regions and used in treating many diseases including malaria and fever. Fractionation of the methanolic extract of its stem bark, using various chromatographic methods has led to the isolation and identification of 3 flavonoids: artocarpesin, artochamin C and kushenol E. And 4 arylbenzofuran derivatives: moracin M, moracin C, moracin L and mulberofuran F. The methanolic extract and the seven isolated compounds were tested for antiplasmodial activity against the chloroquine-resistant FcB1 Plasmodium falciparum strain and cytotoxicity on MCF-7 human breast cancer cells. Relating to the antiplasmodial activity, it was found that all compounds were active against the FcB1 strain of Plasmodium with artocarpesin, koushenol E and mulberrofuran F showing particular potency (with the median inhibitory concentrations IC50 = 2.5-2.6 μg/ml). Cytotoxicity tests performed on MCF-7 cells revealed all the IC50 varying from <1.0 to 5.0 ± 0.6 μg/mL. A structure – activity relationship is discussed
Cytotoxic and Antiplasmodial Xanthones from Pentadesma butyracea
Four new xanthones, butyraxanthones A-D (1-4), were isolated from the stem bark of Pentadesma butyracea, together with six known xanthones (5-10) and a triterpenoid (lupeol). The structures of 1-4 were established by spectroscopic methods. Compounds 1-10 were tested in vitro for antiplasmodial activity against a Plasmodium falciparum chloroquine-resistant strain and for cytotoxicity against a human breast cancer cell line (MCF-7). Nearly all of these xanthones exhibited good antiplasmodial activity, and some of them also demonstrated potent cytotoxicity
Cytotoxicity, nitric oxide and acetylcholinesterase inhibitory activity of three limonoids isolated from Trichilia welwitschii (Meliaceae)
BACKGROUND: Limonoids are highly oxygenated compounds with a prototypical structure. Their occurrence in the plant kingdom is mainly confined to plant families of Meliaceae and Rutaceae. Owing to their wide range of pharmacological and therapeutic properties, this study was aimed at investigating the potential nitric oxide (NO) and acetylcholinesterase (AChE) inhibitory activity and the cytotoxicity of three limonoids: trichilia lactone D5 (1), rohituka 3 (2) and dregeanin DM4 (3), isolated from Trichilia welwitschii C.DC RESULTS: Results indicated that the three limonoids had low cytotoxicity towards Vero cells with LC50 values ranging from 89.17 to 75.82 (μg/L. Compounds (2) and (3) had lower cytotoxicity compared to puromycin and doxorubicin used as reference cytotoxic compounds. Compound (1) (LC50 of 23.55 (μg/L) had good antiproliferative activity against RAW 264.7 cancer cells. At the lowest concentration tested (0.5 μg/mL), compound (2) and (3) released the lowest amount of nitric oxide (2.97 and 2.93 μM, respectively). The three limonoids had anti-AChE activity with IC50 values ranged of 19.13 (μg/L for (1), 34.15 (μg/L for (2) and 45.66 (μg/L for (3), compared to galantamine (IC50 of 8.22 ( g/mL) used as positive control CONCLUSION: The limonoid compounds studied in this work inhibited nitric oxide production in LPS-stimulated macrophages and had anti-AChE activity. Trichilia lactone D5 had potential antiproliferative activity against RAW 264.7 cancer cells. The limonoids had low cytotoxicity towards Vero cells lines. This study provided further examples of the importance of limonoids compounds as potential AChE inhibitors and anti-inflammatory agents targeting the inhibition of NO productio
Modeling an Intelligent E-marketplace Software: Another Outlook of an E-commerce Environment.
Les places de marché virtuelles constituent l\'expression la plus courante des transactions électroniques interentreprises –B2B. Elles permettent, à travers le plus vaste réseau de communication du monde (Internet), de mettre en relation directe d\'affaires des fournisseurs et des acheteurs d\'horizons divers. La réalisation de ces interactions comporte
des points critiques qu\'il convient de traiter de façon optimale pour créer un forum efficace où les participants bénéficient pleinement des offres du marché virtuel. Les aspects concernés comprennent notamment l\'automatisation des procédures, l\'analyse contextuelle approfondie du marché, la facilitation du processus de prise de décisions, les négociations de conditions d\'achat/vente et les services à valeur ajoutée. Notre contribution dans la construction d\'une infrastructure qui prend en compte ces points essentiels se focalise sur la conception architecturale et l\'intégration d\'un module de gestion de connaissances, qui soit assez intelligent pour simplifier la réalisation des aspects susmentionnés des transactions interentreprises.Virtual market places are known to be the most current expression of today\'s business-to-business electronic transactions. Through the worldwide communication network (Internet), virtual markets enable direct business relations
between buyers and suppliers coming from many different horizons. These interactions bring out crucial problems such as procedures automation, transaction and market analysis, decisions taking, value added services and pricing negotiations, which need to be solved in order to create an e-market forum where participants benefit from its offers. Our contribution in the building of such an infrastructure focuses on the architectural design of an embedded knowledge management module intelligent enough to streamline the process of tackling the above mentioned aspects of a business-to-business (B2B) emarketplace. Keywords: e-intelligence, e-business, e-marketplace, gestion des connaissances, systèmes à base de règles.; e-intelligence, e-business, e-marketplace, knowledge management, rules-based systems. Journal des Sciences Pour l\'Ingénieur. Vol. 7 2006: pp. 45-5
Effects of Mondia whitei extracts on the contractile responses of isolated rat vas deferens to potassium chloride and adrenaline
Objective: To investigate the effects of the methylene
chloride:methanol (CH2Cl2:MeOH, 1:1) extract of the dried roots of
Mondia whitei Linn and its hexane and methanol fractions on
potassium chloride (KCl) and adrenaline (Adr)-induced contractions of
rat vas deferens. Materials and Methods: Isolated strips of normal
adult rat vas deferens were mounted in a Ugo Basile single-organ bath
containing Krebs solution. Cumulative concentration-response curves of
KCl (1-7 x 10-2 M ) and adrenaline (1.21-8.45 x 10-7 M ) were
established in the absence and presence of M. whitei (50-400
μg/ml). In separate experiments, after obtaining a stable plateau
of contractions with KCl (60 m M ), M. whitei samples (50-400
μg/ml) were added cumulatively to relax the preparation. In KCl
(60 m M ), containing depolarizing medium, cumulative
concentration-contraction curve to CaCl2 (2-14 x 10-2 M ) was elicited
in the absence and presence of the hexane fraction of M. whitei (50-400
μg/ml). Results: All the M. whitei samples produced rightward
shift of the concentration-response curves to KCl and Adr. At high
concentration of the plant extracts (400 μg/ml), a decrease of the
maximal response to the contractile agents was observed compared with
that obtained with the control. All the three extracts produced
concentration-dependent relaxation of the plateau of contraction
induced by KCl and the hexane fraction appeared to be the more potent.
In calcium-free physiological salt solution, the hexane fraction of M.
whitei produced rightward shift to the concentration-response curve to
CaCl2 and completely abolished the contractile effect of calcium at
high concentration (400 μg/ml). Conclusion: It is concluded that
M. whitei extracts antagonized the contractile responses to KCl and Adr
in isolated rat vas deferens, which could be due to the blockade of
voltage-operated calcium channels