670 research outputs found

    Natural Products and Tropical Diseases

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    In vitro antileishmanial and cytotoxicity activities of essential oils from Haplophyllum tuberculatum A. Juss leaves, stems and aerial parts

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    Background: Plants used for traditional medicine produce diverse and complex secondary metabolites exhibiting various medicinal properties. The medicinal plant Haplophyllum tuberculatum is used by native people against malaria and parasitic infections. Methods: In this study and in order to contribute for the search of new natural drugs for leishmaniasis, the essential oils of H. tuberculatum leaves, stems and aerial parts (leaves+stems) collected in two different periods, 2013 and 2015, and their components by GC/FID and GC/MS analyses were investigated. Those collected in 2013 were also re-analyzed two years later. The extracted oils were screened in vitro for anti-leishmanial activity on Leishmania mexicana mexicana (L.m.m.) promastigotes and cytotoxicity on the Chinese Hamster Ovary (CHO) cell line. Limonene (1.5 – 8%), its isomers (R- (+)-limonene and S-(-)-limonene), linalool and octanol were also tested. Results: Results showed that the chemical composition varied according to the year of collection. Though major compounds remain almost the same, qualitative and quantitative variations in the composition of the EOs can be observed between the two years of collection, with some minor compounds identified only in one type of samples. Variation in the composition were also observed in the re-analyzed volatile oils, showing stability concerns. The essential oils and R-(+)-limonene showed moderate anti-leishmanial activity. Their IC50 range from 6.48 to 50.28 μg/ml. Cytotoxicity assays for theses volatile extracts, R- (+)-limonene and S- (-)-limonene on CHO cells showed relatively potent cytotoxicity with a selectivity index <10. Their CC50 range from 27.79 to 82.56 μg/ml. Conclusions: The findings of the present study demonstrated that H. tuberculatum might not be considered as a natural source for production of new anti-leishmanial agents without further analyzing its eventual in vivo toxicity as well as that of major pure compounds

    Chemical composition and antimicrobial activity of essential oils of Ocimum basilicum, Ocimum canum and Ocimum gratissimum in function of harvesting time

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    BACKGROUND: The aim of present the study was to investigate the chemical composition and the antimicrobial activity of essential oils of Ocimum basilicum, Ocimum canum and Ocimum gratissimum from Benin as affected by harvesting time. The chemical composition of hydrodistillated essential oils were analyzed by GC-FID (gas chromatography – flame ionization detector) and GC-MS (gas chromatography-mass spectrometry). Disc diffusion and broth microdilution assays were used to evaluate the antibacterial activity of essential oils against two foodborne pathogens. RESULTS: Based on the composition analysis, major components were as follows: estragol (43.0 -44.7 %) and linalool (24.6 -29.8 %) in O. basilicum oils; carvacrol (12.0 -30.8 %) and p-cymene (19.5 -26.2 %) in O. canum oils; thymol (28.3 -37.7 %) and γ-terpinene (12.5 -19.3 %) in O. gratissimum oils. The tested oils and their components exhibited notable antimicrobial activities against Listeria monocytogenes and Salmonella typhimurium. The O. canum and O. gratissimum oils collected at 7h and 19h showed significant higher activities against L. monocytogenes and S. typhimurium (MICs and MBCs 0.34 – 2.5 µL/mL) (p < 0.05), whereas O. basilicum showed lower activity (MICs and MBCs 2.0 – 8.0 µL/mL) at any daytime of harvest, the weakest being at 19h (MIC and MBC 12.0 – 32.0 µL/mL). CONCLUSION: The daytime of harvest can influence the composition of oils and their activities on bacteria

    Variation diurne de la composition chimique et influence sur les propriétés antimicrobiennes de l’huile essentielle de Ocimum canum Sims cultivé au Bénin

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    L&rsquo;huile essentielle de Ocimum canum Sims (Lamiaceae) obtenue par hydrodiffusion &agrave; diff&eacute;rents moments de la journ&eacute;e a &eacute;t&eacute; analys&eacute;e par GC/FID et GC/SM puis test&eacute;e sur diff&eacute;rentes bact&eacute;ries par la microtechnique de dilution. Le rendement et la composition chimique de l&rsquo;huile varient selon le temps et l&rsquo;ensoleillement. Abondant le matin &agrave; 7 heures (1,71&plusmn;0,01%), le rendement d&eacute;cro&icirc;t progressivement avec l&rsquo;augmentation des rayons solaires, jusqu&rsquo;&agrave; son minimum &agrave; 13 heures (1,35&plusmn;0,01%) quand le soleil est au z&eacute;nith, avant de cro&icirc;tre &agrave; nouveau &agrave; sa valeur la plus &eacute;lev&eacute;e (1,78&plusmn;0,02% &agrave; 19 h) au couch&eacute; du soleil. Plus de 54 compos&eacute;s repr&eacute;sentant pr&egrave;s de 98% des hydrodiffusats, ont &eacute;t&eacute; identifi&eacute;s dans les diff&eacute;rents &eacute;chantillons. Les principaux sont : &alpha;-thuj&egrave;ne (5,56 &agrave; 7,85%), &beta;-myrcene (2 &agrave; 6,94%), &delta;-3-car&egrave;ne (3,07 &agrave; 4,84%), p-cym&egrave;ne (14,61 &agrave; 22,8%), g-terpin&egrave;ne (6,05 &agrave; 10,7%), carvacrol (7,94 &agrave; 30,8%), &beta;-caryophyll&egrave;ne (0,15 &agrave; 18,86%) et &beta;- s&eacute;lin&egrave;ne (2,74 &agrave; 14,41%). Les taux de certains constituants comme &beta;-caryophyll&egrave;ne et &beta;-s&eacute;lin&egrave;ne croissent avec l&rsquo;ensoleillement contrairement &agrave; ceux du carvacrol, p-cym&egrave;ne. Cette variation diurne perturbe la synergie d&rsquo;action des constituants de l&rsquo;huile qui pr&eacute;sentent une forte activit&eacute; inhibitrice (0,38 &agrave; 7,19 mg/ml) sur Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25923, Acinetobacter baumannii ATCC 19609 et Staphylococcus aureus r&eacute;sistante 1199B NorA. Les huiles obtenues &agrave; 7 heures et 19 heures sont les plus efficaces &agrave; faible concentration (0,38 &agrave; 2,88 mg/ml). Pour la premi&egrave;re fois, l'interaction est d&eacute;montr&eacute;e entre variation diurne de la composition chimique et propri&eacute;t&eacute;s antimicrobiennes de l'huile essentielle de Ocimum canum Sims du B&eacute;nin.Keywords: Ocimum americanum, compos&eacute;s volatils, Ch&eacute;motype &agrave; carvacrol Variation diurne-Activit&eacute; antibact&eacute;rienn

    Diethyl 2-[(2-benzyl-1-phenyl­sulfonyl-1H-indol-3-yl)methyl­ene]malonate

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    In the title compound, C29H27NO6S, the sulfonyl-bound phenyl ring is almost perpendicular to the indole ring system [dihedral angle = 87.96 (6)°], while the benzyl­phenyl ring is oriented at an angle of 76.8 (7)°. An intra­molecular C—H⋯O hydrogen bond is observed. In the crystal structure, mol­ecules are linked into a zigzag C(10) chain along the b axis by inter­molecular C—H⋯O hydrogen bonds

    When Inequality is Equitable: Validity, Propriety and Third Party Allocations

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    The author summarizes theories of equity and distributive justice that predict actors use legitimate distribution rules to act to maintain or to restore equity. He elaborates those ideas, distinguishing legitimacy based on validity (socially supported) from propriety (acceptance by the focal actor). Experimental research showed strong effects of both types of legitimacy on behavior, with validity having slightly stronger effects.This research was supported by a grant from the National Science Foundation (SOC #7817^3<»), Morris Zelditch, Jr.» Principal Investigator. Computations were supported by a grant from the Office of the Dean of Graduate Studies and Research at Stanford University
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