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EN
In spite of the long history of therapeutic use of buds from different birch species in folk medicine the existing information on their chemical composition is insufficient. The main goal was to develop a method for GC-MS determination of the chemical profile of birch buds as well as their antimicrobial activity. 150 substances of different classes were identified in Betula litwinowii buds. The volatile elements of the buds were mainly represented by sesquiterpene compounds. Ether extracts also contained other biologically active components such as flavonoids and triterpenoids. However, a particular feature of this fraction was the high content of sesquiterpene phenylpropenoids, including esters of ferulic and caffeic acids with caryophyllene-type alcohols that had not been previously found in any biological samples. Apart from carbohydrates, a series of free amino acids were detected in methanol extracts. The antimicrobial activity of the ether extracts of the buds was observed against all of the microorganisms tested, with MIC values from 0.04 to 0.08 mg mL-1 for Gram-positive bacteria and Candida albicans. However, their inhibitory activities against tested Gram-negative bacteria were rather occasional.
EN
2-Amino-4-(2’-n-butyl-4’-chloro-1’-H-imidazol-5’-yl)-6-aryl nicotinonitriles. (2a-2j); 2-Methoxy-4-(2’-n-butyl-4’-chloro-1’-H-imidazol-5’-yl)-6-aryl nicotinonitriles. (3a-3j) have been synthesized. The products have been assayed for their antimicrobial activity against Gram +ve bacteria and Gram –ve bacteria and fungi. The products have been characterized by IR, 1HNMR, Mass Spectra and TLC.
EN
Attempts have been made to prepare for the first time the octasubstituted-triphenodioxazines and triphenodithiazines heterocycles by cyclisation of 3,6-dichloro-2,5-bis(2′,4′,5′-trichloroanilino)-1,4-benzoquinone and condensation. This wasfollowed by cyclisation of substituted 2-aminobenzenethiol respectively with chloranil and bromanil in ethanolic solution of fused sodium acetate in the presence of benzoyl chloride in nitrobenzene. Their structures were confirmed on the basis of their chemical and spectral analyses. Moreover, the biological activity of these compounds was evaluated against the test organisms viz - E.coli, S. aureus, B. subtilis, M.luteus and C. albicans. These compounds synthesized from 2,4,5-trichloroaniline appeared to possess significant antimicrobial activities and an explicit correlation between structure and biological activity was also observed. [...]
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A new series of twenty four derivatives of pyrano[3,2-c]chromene IVa-x bearing 1H-pyrazole were synthesized by a one pot, base-catalyzed cyclocondensation reaction of 1H-pyrazole-4-carbaldehyde Ia-l, malononitrile II and 4-hydroxycoumarin IIIa-b. All the synthesized compounds were characterized by elemental analysis, FT-IR, 1H NMR and 13C NMR spectral data. All the synthesized compounds were screened against six bacterial pathogens, namely B. subtilis, C. tetani, S. pneumoniae, S. typhi, V. cholerae, E. coli and for antifungal activity against two fungal pathogens, A. fumigatus and C. albicans using the broth microdilution MIC method. Some of the compounds were found to be equipotent or more potent than commercial drugs against most of employed strains, as evident from the screening data. [...]
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The main goal of our study is the analysis of data obtained from molecular modeling for a series of imidazole derivatives that possess strong antifungal activity. The research was designed to use artificial neural network (ANN) analysis to determine quantitative relationships between the structural parameters and anti-Streptococcus pyogenes activity of a series of imidazole derivatives. ANN in association with quantitative structure-activity relationships (QSAR) represents a promising tool in the search for drug candidates among the practically unlimited number of possible derivatives. In this work, a series of 286 imidazole derivatives presented as cationic three-dimensional structures was used. The activity was expressed as a logarithm of the reciprocal of the minimal inhibitory concentrations, log 1/MIC. Multilayer perceptron ANN was used for predictions of antimicrobial potency of new imidazole derivatives on the basis of their structural descriptors. The obtained correlation coefficient equaled 0.9461 for the learning set, 0.9060 for the validation set and 0.8824 for the testing set of imidazole derivatives. Hence, satisfactory and practically useful predictions of anti-Streptococcus pyogenes activity for a series of imidazole derivatives was obtained, supporting the future successful interpretation of QSAR analysis for those compounds.
EN
5-(2’-n-butyl-4’-chloro 1’-H-imidazol- 5’-yl)-3-aryl-4, 5-dihydro-1-H-pyrazoles. (2a-2j); 1-[5’-(2”-n-butyl-4”- chloro-1”-H-imidazol-5”-yl)-3’-Aryl-4’, 5’-dihydro-1’-H-pyrazol-1-yl]-ethanones. (3a-3j); 5-(2’-n-butyl-4’-chloro-1’-H-imidazol-5’-yl)-3-Aryl-1-phenyl-4, 5-dihydro-1-H-pyrazoles. (4a-4j) have been synthesized. The products have been assayed for their antimicrobial activity against Gram +ve bacteria and Gram –ve bacteria and antifungal activity. The products have been characterised by IR, 1HNMR, Mass Spectra and TLC.
EN
Comparative studies were performed on a series of 2,4-di and 2,3,4-trisubstituted benzimidazo[1,2-a]pyrimidines, which were synthesized with conventional and microwave heating methods. In microwave irradiation method, approximately, 95–97.5% of the reaction time was increased and 1–45% yield increase was obtained. All compounds were able to inhibit the growth of the screened microorganisms in vitro with MIC values between 3.9–250 μg mL−1. The highest activity was expressed by compound IIId (2,4-diphenyl-benzo[4,5]imidazo[1,2-a] pyrimidine), which has the MIC value of 3.9 μg mL−1 and 31.2 μg mL-1 for Penicillium natatum ATCC 24791 and E. faecalis ATCC 29212, respectively. [...]
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Borneol is a monoterpene that is a part of traditional Chinese and Japanese medicine. (−) borneol reacted with methanesulfonyl chloride in THF/pyridine to afford the new 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methane sulfonate derivative in excellent yield. The product is characterized by H1NMR, C13NMR, mass spectroscopy as well as elemental analysis and its structure was identified by X-ray single crystal diffraction. The packing of 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methanesulfonate exhibits the non-classical C-H···O hydrogen bonding in C(4) and R22(8) chain and ring motifs as structural determinants. This was also confirmed by the analysis of Hirshfeld surfaces. The 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methane sulfonate antimicrobial activity was tested and compared with its parent (−) borneol against three different pathogens. Particularly, 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methane sulfonate showed high sensitivity, compared to Chloramphenicol reference material, against Escherichia coli. [...]
EN
Finding healing power in plants is an ancient idea, and people of all continents and civilization have been using plants in one form or the other for poultices or as decoctions. Alangium salvifolium (Linn), family Alangeaceae, is a tree that grows in the wild throughout India. The plant has been used in the Indian traditional system of medicine for skin diseases (e.g. leucoderma), articular diseases, and anti-inflammation, anti-poisonous, anti-pyretic, and anti-emetic requirements. However, no scientific evidence is available regarding its antimicrobial activity. An investigation of Alangium salvifolium as an antimicrobial activity agent is the objective of our present study. The ATCC culture used in this study was collected from department of Microbiology, G.M.C., Bhopal (M.P.). Shade dried crude powder (200 grams) of seed of Alangium salvifolium was separately extracted with methanol in a soxhelt apparatus. The Antimicrobial activities were then studied by applying the Disc–Diffusion method. Our results indicate that the observed antimicrobial activity of the fraction appears to be due to unknown secondary metabolites in it. H.P.L.C. (high performance liquid chromatography) and chemical studies may, thus be useful in analyzing the presence of unknown secondary metabolites in the fractions.
EN
A series of N-(6-methylbenzothiazolyl)-2,3,5,6-tetrasubstituted-4-(aryl)-1,4-dihydropyridines were synthesized by reaction of 2-amino-6-methylbenzothiazole, aromatic aldehyde and active methylene compound in methanol by conventional, as well as, microwave irradiation (solvent free and solid support) methods. The microwave irradiation technique gives better yield and shorter reaction time. Among solid supported microwave irradiation better yields are obtained in acidic alumina as compared to silica, neutral alumina, and basic alumina. All compounds were tested for antibacterial and antifungal activities and results have been compared with standard drugs. Entomological activities were also tested. The results showed that a change in the substitution pattern in 1,4-dihydropyridine derivatives may cause a marked effect on their antimicrobial activity. [...]
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Ru(III) complexes of the type [RuXB(L)2] have been prepared by the reaction of 3,4-dihydropyrimidin-2(1H)-ones/thiones (HL1–HL4) with the precursors of the type [RuX3B3] where X=Cl or Br; B=PPh3 or AsPh3 and L is the deprotonated ligand. The synthesized complexes were characterized by physico-chemical methods, electrochemical and magnetic moment data. The catalytic efficiency of the complexes were examined in the oxidation of alcohols and antimicrobial studies were also carried out. [...]
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