Home About us Contact
|
Home About us Contact | ||
|
|
||
Antibacterial
Terms modified by Antibacterial Selected AbstractsHigh Antibacterial and Antifungal Activity of Silver Monodispersed Nanoparticles Embedded in a Glassy Matrix,ADVANCED ENGINEERING MATERIALS, Issue 7 2010Leticia Esteban-Tejeda Silver doped glass powders have been obtained starting from vitellinate/nAg and montmorillonite/nAg. These powders have shown a high biocide activity against the three different types of microorganisms studied: Escherichia coli (gram-negative bacteria), Micrococcus luteus (gram-positive-bacteria), and Issatchenkia orientalis (yeast). It was found that these glasses keep constant the silver concentration even below the cytotoxic limit. Therefore we interpret that silver doped glasses play the role of dosing devices. [source] Antibacterial and Abrasion-Resistant Alumina Micropatterns,ADVANCED ENGINEERING MATERIALS, Issue 7 2009Laura Treccani In this work, a novel processing route to fabricate alumina surfaces that feature remarkable antibacterial and abrasion-resistant properties is reported. By combining micropatterning with antibacterial enzymes and alumina nanoparticles, we fabricated surfaces that present a feasible and highly interesting alternative to improve, e.g., systems employed for water transport containing abrasive agents, aggressive media and microorganisms. [source] Biochemical characterization and inhibitor discovery of shikimate dehydrogenase from Helicobacter pyloriFEBS JOURNAL, Issue 20 2006Cong Han Shikimate dehydrogenase (SDH) is the fourth enzyme involved in the shikimate pathway. It catalyzes the NADPH-dependent reduction of 3-dehydroshikimate to shikimate, and has been developed as a promising target for the discovery of antimicrobial agent. In this report, we identified a new aroE gene encoding SDH from Helicobacter pylori strain SS1. The recombinant H. pylori shikimate dehydrogenase (HpSDH) was cloned, expressed, and purified in Escherichia coli system. The enzymatic characterization of HpSDH demonstrates its activity with kcat of 7.7 s,1 and Km of 0.148 mm toward shikimate, kcat of 7.1 s,1 and Km of 0.182 mm toward NADP, kcat of 5.2 s,1 and Km of 2.9 mm toward NAD. The optimum pH of the enzyme activity is between 8.0 and 9.0, and the optimum temperature is around 60 °C. Using high throughput screening against our laboratory chemical library, five compounds, curcumin (1), 3-(2-naphthyloxy)-4-oxo-2-(trifluoromethyl)-4H -chromen-7-yl 3-chlorobenzoate (2), butyl 2-{[3-(2-naphthyloxy)-4-oxo-2-(trifluoromethyl)-4H -chromen-7-yl]oxy}propanoate (3), 2-({2-[(2-{[2-(2,3-dimethylanilino)-2-oxoethyl]sulfanyl}-1,3-benzothiazol-6-yl)amino]-2-oxoethyl}sulfanyl)- N -(2-naphthyl)acetamide (4), and maesaquinone diacetate (5) were discovered as HpSDH inhibitors with IC50 values of 15.4, 3.9, 13.4, 2.9, and 3.5 µm, respectively. Further investigation indicates that compounds 1, 2, 3, and 5 demonstrate noncompetitive inhibition pattern, and compound 4 displays competitive inhibition pattern with respect to shikimate. Compounds 1, 4, and 5 display noncompetitive inhibition mode, and compounds 2 and 3 show competitive inhibition mode with respect to NADP. Antibacterial assays demonstrate that compounds 1, 2, and 5 can inhibit the growth of H. pylori with MIC of 16, 16, and 32 µg·mL,1, respectively. This current work is expected to favor better understanding the features of SDH and provide useful information for the development of novel antibiotics to treat H. pylori -associated infection. [source] Treatment development for systemic Tetrahymena sp. infection in guppies, Poecilia reticulata PetersJOURNAL OF FISH DISEASES, Issue 6 2010M Pimenta Leibowitz Abstract Antibacterial and antiparasitic agents and a cysteine protease inhibitor (E-64) were tested against Tetrahymena infection, a serious problem in guppy production worldwide. Chemicals were tested in vitro by a colorimetric assay for Tetrahymena survival. The most effective were niclosamide, albendazole and chloroquine, with 23%, 35% and 60% survival, respectively, following 2-h exposure to 100 ppm. Longer incubation periods resulted in greater reductions in survival. Niclosamide was further studied in vivo at different dosages, administered orally to Tetrahymena -infected guppies. Mortality rates were significantly lower in all treatment groups; in trial I, 30% and 33% mortality in 5 and 40 mg kg,1 niclosamide-fed fish vs. 59% mortality in controls; in trial II, 35%, 13% and 10% in 50, 100 and 200 mg kg,1 niclosamide-fed fish vs. 64% in controls. The effect of the cysteine protease inhibitor E64 was tested in tissue culture, by measuring histolytic activity of the parasite (Tet-NI) on a guppy-fin cell line, based on cell depletion. Tet-NI feeding activity was significantly reduced following pretreatment with E-64 relative to non-treated Tet-NI. E-64-pretreated Tet-NI was injected i.p. into guppies: recorded mortality rates were significantly lower (35%) than that in non-treated Tet-NI (60%), suggesting inhibition of the parasite's cysteine protease as a possible therapeutic approach. [source] Parallel and antiparallel dimers of magainin 2: their interaction with phospholipid membrane and antibacterial activityJOURNAL OF PEPTIDE SCIENCE, Issue 10 2002Yasuhiro Mukai Abstract Magainin 2 (M2) forms pores by associating with several other M2 molecules in lipid membranes and shows antibacterial activity. To examine the effect of M2 dimerization on biological activity and membrane interaction, parallel and antiparallel M2 dimers were prepared from two monomeric precursors. Antibacterial and haemolytic activities were enhanced by dimerization. CD measurements showed that both dimers and monomers have an ,-helical structure in the presence of lipid vesicles. Tryptophan fluorescence shift and KI quenching studies showed that all the peptides were more deeply embedded in acidic liposomes than in neutral liposomes. Experiments on dye-leakage activity and membrane translocation of peptides suggest that dimers and monomers form pores through lipid membranes, although the pore formation may be accompanied by membrane disturbance. Although dimerization of M2 increased the interaction activity with lipid membranes, no appreciable difference between the activities of parallel and antiparallel M2 dimers was observed. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd. [source] Antibacterial, antiviral, antiproliferative and apoptosis-inducing properties of Brackenridgea zanguebarica (Ochnaceae)JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 8 2006Maren Möller Brackenridgea zanguebarica is a small tree that is used in traditional African medicine as a type of cure-all for many diseases, including the treatment of wounds. The yellow bark of B. zanguebarica was used for the preparation of an ethanolic extract, which was tested in various concentrations against eleven bacteria, Herpes simplex virus type 1 (HSV-1) and different human tumour cell lines. The extract that contains different polyphenolic substances like calodenin B. Cell growth inhibition, assessed via MTT-assay, was found in all tested human cell lines with IC50 values (concentration of extract that reduced cell viability by 50%) between 33 ,g dry extract/mL for HL-60 human myeloid leukaemia cells and 93 ,g dry extract/mL for HaCaT human keratinocytes. Staining with Annexin-V-FLUOS and JC-1 followed by subsequent analysis via flow cytometry revealed significant apoptosis-inducing properties. Analysis of caspase activity using a fluorogenic caspase-3 substrate showed a significant caspase activity in Jurkat T-cells after incubation with the extract. The bark extract had a pronounced activity against free HSV-1 and a strong antibacterial activity against Gram-positive strains (MICs: 6,24 ,g dry extract/mL), which are often involved in skin infections. Additionally, no irritating properties of the extract could be observed in hen-egg test chorioallantoic membrane (HET-CAM) assay. These findings give a rationale for the traditional use of B. zanguebarica and are a basis for further analysis of the plant's components, their biological activity, and its use in modern phytotherapy. [source] Antibacterial and Hemolytic Activities of Quaternary Pyridinium Functionalized PolynorbornenesMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 5 2008Tarik Eren Abstract In this study, amphiphilic polyoxanorbornene with different quaternary alkyl pyridinium side chains were synthesized. The biological efficiencies of these polymers, with various alkyl substituents, were determined by bacterial growth inhibition assays and hemolytic activity (HC50) against human red blood cells (RBCs) to provide selectivity of these polymers for bacterial over mammalian cells. A series of polymers with different alkyl substituents (ethyl, butyl, hexyl, octyl, decyl and phenylethyl) and two different molecular weights (3 and 10 kDa) were prepared. The impact of alkyl chain length divided the biological activity into two different cases: those with an alkyl substituent containing four or fewer carbons had a minimum inhibitory concentration (MIC) of 200 µg,·,mL,1 and a HC50 greater than 1,650 µg,·,mL,1, while those with six or more carbons had lower MICs,,,12.5 µg,·,mL,1 and HC50,,,250 µg,·,mL,1. Using MSI-78, the potent Magainin derivative which has an MIC,=,12.0 µg,·,mL,1 and HC50,=,120 µg,·,mL,1, as a comparison, the polymers with alkyl substituents ,C4 (four carbons) were not very potent, but did show selectivity values greater than or equal to MSI-78. In contrast, those with alkyl substituents ,C6 were as potent, or more potent, than MSI-78 and in three specific cases demonstrated selectivity values similar to, or better than, MSI-78. To understand if these polymers were membrane active, polymer induced lipid membrane disruption activities were evaluated by dye leakage experiments. Lipid composition and polymer hydrophobicity were found to be important factors for dye release. [source] Antibacterial, spectral and thermal aspects of drug based-Cu(II) mixed ligand complexesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 10 2009G. J. Kharadi Abstract The antibiotic agent clioquinol is well known for its drug design and coordinating ability towards metal ions. Copper(II) mixed-ligand complexes of clioquinol with various uninegative bidentate ligands were prepared. The structure of the synthesized complexes was characterized using elemental analyses, infrared spectra, 1H-NMR spectra, electronic spectra, magnetic measurements, FAB mass spectrum and thermo gravimetric analyses. The kinetic parameters such as order of reaction (n) and the energy of activation (Ea) are reported using the Freeman,Carroll method. The pre-exponential factor (A), the activation entropy (,S#), the activation enthalpy (,H#) and the free energy of activation (,G#) were calculated. Complexes were also screened for their in vitro antibacterial activity against a range of Gram-positive and Gram-negative bacteria in order to set the precursors for anti-tumourigenic agent. Copyright © 2009 John Wiley & Sons, Ltd. [source] Facile Synthesis and Antibacterial, Antitubercular, and Anticancer Activities of Novel 1,4-DihydropyridinesARCHIV DER PHARMAZIE, Issue 6 2010Kalam Sirisha Abstract A series of twenty new 4-substituted-2,6-dimethyl-3,5-bis- N -(heteroaryl)-carbamoyl-1,4-dihydropyridines have been prepared from a three-component one-pot condensation reaction of N -heteroaryl acetoacetamide, an aromatic/heteroaromatic aldehyde, and ammonium acetate under four different experimental conditions. Except for the conventional method, all the experimental conditions were simple, eco-friendly, economical, and the reactions were rapid and high-yielding. The methods employed have been compared in terms of yields, cost, and simplicity. The synthesized compounds were characterized by different spectroscopic techniques and evaluated for their in-vitro anticancer, antibacterial, and antitubercular activities. Amongst the compounds tested, compound 25 exhibited the highest anticancer activity while compounds 14 and 18 exhibited significant antibacterial and antitubercular activities. [source] Synthesis, Cytotoxicity by Bioluminescence Inhibition, Antibacterial and Antifungal Activity of ([1,2,4]Triazolo[1,5- c]quinazolin-2-ylthio)carboxylic Acid AmidesARCHIV DER PHARMAZIE, Issue 11 2009Lyudmila N. Antipenko Abstract We report in this work the synthesis, cytotoxicity, and antimicrobial activity of ([1,2,4]triazolo[1,5- c]quinazolin-2-ylthio)carboxylic acid amides 4,7 in connection with our previous research in the preparation of triazoloquinazoline derivatives. Due to simplicity, general availability of starting materials, and high yields, the most reliable method of synthesis appeared to be the one with N,N -carbonyldiimidazole activation stage. The chemical structures of all obtained substances were deduced from FT-IR, 1H-NMR, EI-MS, and LC-MS spectral data. The results of cytotoxicity evaluated by bioluminescence inhibition of bacterium Photobacterium leiognathi, strain Sh1 showed that compounds 4.1, 4.6, and 6.1 were the most cytotoxic. Investigation of the antimicrobial and antifungal activity of amides 4,7 (concentration 5 mg/mL) was carried out by the stiff-plate agar-diffusion method. We found that the compounds possessed low (4.1, 4.7) antifungal activity against Candida tenuis and strong (4.21, 5.1, 5.9) or inefficient (4.7, 4.12, 4.16) activity against Aspergillus niger. Substances 5.1 and 5.9 slightly affected Mycobacterium luteum. Staphylococcus aureus was resistant to all obtained substances, and only the n -butyramide derivatives 7.1 and 7.5 inhibited the growth of Escherichia coli. Hence, there was no strong correlation between bioluminescence inhibition and antimicrobial activity of the investigated substances. [source] Synthesis, Antibacterial and Antifungal Activities of Novel 1,2,4-Triazolium DerivativesARCHIV DER PHARMAZIE, Issue 7 2009Yan Luo Abstract A series of novel 1,2,4-triazolium derivatives was synthesized starting from commercially available 1H -1,2,4-triazole, 2,4-dichlorobenzyl chloride, or 2,4-difluorobenzyl bromide. Their antibacterial and antifungal activities were evaluated against Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Bacillus proteus, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans ATCC 76615, and Aspergillus fumigatus. All structures of the new compounds were confirmed by NMR, IR, and MS spectra, and elemental analyses. The antimicrobial tests showed that most of synthesized triazolium derivatives exhibit significant antibacterial and antifungal activities in vitro. 1-(2,4-Difluorobenzyl)-4-dodecyl-1H -1,2,4-triazol-4-ium bromide and 1-(2,4-Dichlorobenzyl)-4-dodecyl-1H -1,2,4- triazol-4-ium bromide were the most potent compounds against all tested strains with the MIC values ranging from 1.05 to 8.38 ,M. They exhibited much stronger activities than the standard drugs chloramphenicol and fluconazole which are in clinical use. The results also showed that the antimicrobial activities of triazolium derivatives depend upon the type of substituent, the length of the alkyl chain, and the number of triazolium rings. [source] ChemInform Abstract: Synthesis of New 4-Pyrrol-1-yl Benzoic Acid Hydrazide Analogues and Some Derived Oxadiazole, Triazole and Pyrrole Ring Systems: A Novel Class of Potential Antibacterial and Antitubercular Agents.CHEMINFORM, Issue 10 2009S. D. Joshi Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Synthesis, Antibacterial, Antiasthmatic and Antidiabetic Activities of Novel N-Substituted-2-(4-phenylethynyl-phenyl)-1H-benzimidazoles and N-Substituted 2(4-(4,4-Dimethyl-thiochroman-6-yl-ethynyl)-phenyl)-1H-benzimidazoles.CHEMINFORM, Issue 39 2008Ramanatham Vinodkumar Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Synthesis of Heterocyclic and Non-Heterocyclic Entities as Antibacterial and anti-HIV Agents.CHEMINFORM, Issue 50 2006R. B. Patel Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis and Studies of Novel Homoveratryl Based Thiohydantoins as Antibacterial as well as anti-HIV Agents.CHEMINFORM, Issue 47 2006R. B. Patel Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Antibacterial and Antifungal Studies on Some New Acetylcinnolines and Cinnolinyl Thiazole Derivatives.CHEMINFORM, Issue 47 2006B. Narayana Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Chemoselective Synthesis of Heterocyclic Derivatives of 18-nor Equilenine, 16-Substituted-12H-11-oxa-15-aza-17-thia-cyclopenta[a]phenanthrenene and Their in vitro Evaluation of Antibacterial and Antifungal Activity.CHEMINFORM, Issue 40 2006N. J. Malviya Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis, Antibacterial and Surface Activity of 1,2,4-Triazole Derivatives.CHEMINFORM, Issue 26 2006Refat El-Sayed Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Heterocyclic Synthesis: A Convenient Route to Some 2-Mercapto 1,3,4-Oxadiazole and Green Chemistry Microwave-Induced One-Pot Synthesis of 2-Aryl 1,3,4-Oxadiazole in Quinazolone and Their Antibacterial and Antifungal Activity.CHEMINFORM, Issue 49 2005A. R. Desai Abstract For Abstract see ChemInform Abstract in Full Text. [source] Syntheses, in vitro Antibacterial and Cytotoxic Activities of a Series of 3-Substituted Succinimides.CHEMINFORM, Issue 13 2005Frederic Zentz Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of Isoxazolylpyrazolo[3,4-d]thiazoles and Isoxazolylthiazoles and Their Antibacterial and Antifungal Activity.CHEMINFORM, Issue 17 2004E. Rajanarendar Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis, Antibacterial and Immunotropic Activity of Polyfluoroalkyl-N-arylcarbamates (III), (VI).CHEMINFORM, Issue 19 2003Yu. N. Studnev No abstract is available for this article. [source] Synthesis and Reactions of Some New 2,3-Dihydro-5H-5,7-diarylthiazolo[3,2-a]pyrimidine-3-one Derivatives and Their Antibacterial and Fungicidal Activity.CHEMINFORM, Issue 16 2003M. A. Salama Abstract For Abstract see ChemInform Abstract in Full Text. [source] Two New Sesquiterpenes from the Chinese Herb Halenia elliptica and Their Antibacterial and Antitumor Activity.CHEMINFORM, Issue 7 2003Jingqiu Dai Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of 5-Arylidene-2-aryl-3-(1,2,4-triazoloacetamidyl)-1,3-thiadiazol-4-ones as Antibacterial, Antifungal, Analgesic and Diuretic Agents.CHEMINFORM, Issue 2 2003S. K. Srivastava Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Novel Functionalized Pyrido[2,3-g]quinoxalinones as Antibacterial, Antifungal and Anticancer Agents.CHEMINFORM, Issue 16 2002Antonio Carta Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Synthesis of Allyl-cyclopropyl Alcohols and Allyl-1,5-hexadien-3-ols and Investigation of Their Antibacterial and Antifungal Activities.CHEMINFORM, Issue 4 2001S. Servi Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] The presence of conifer resin decreases the use of the immune system in wood antsECOLOGICAL ENTOMOLOGY, Issue 3 2008GRÉGOIRE CASTELLA Abstract 1.,Wood ants (Formica paralugubris) incorporate large amounts of solidified conifer resin into their nest, which reduces the density of many bacteria and fungi and protects the ants against some detrimental micro-organisms. By inducing an environment unfavourable to pathogens, the presence of resin may allow workers to reduce the use of their immune system. 2.,The present study tested the hypothesis that the presence of resin decreases the immune activity of wood ants. Specifically, three components of the humoral immune defences of workers kept in resin-rich and resin-free experimental nests (antibacterial, lytic, and prophenoloxidase activities) were compared. 3.,The presence of resin was associated with reduced bacterial and fungal densities in nest material and with a small decrease in worker antibacterial and lytic activities. The prophenoloxidase activity was very low in all workers and was not affected by the presence of resin. 4.,These results suggest that collective medication with resin reduces pathogen pressure, which in turn decreases the use of the inducible part of the immune system. More generally, the use of plant secondary compounds might be an efficient and economical way to fight pathogens. [source] Molecular Interaction between a Gadolinium,Polyoxometalate and Human Serum AlbuminEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 34 2009Li Zheng Abstract Polyoxometalates (POMs) show promising antibacterial, antiviral (particularly anti-HIV), antitumor, and anticancer activities, but the mechanism of these potential therapeutic effects remains to be elucidated at the molecular level. The interaction between the Gd-containing tungstosilicate [Gd(,2 -SiW11O39)2]13, and human serum albumin (HSA) was studied by several techniques. Fluorescence spectroscopy showed an energy transfer between the single tryptophan residue of HSA and the POM. Circular dichroism led to the conclusion that the POM significantly altered the secondary structure of HSA. Isothermal titration calorimetry revealed an enthalpy-driven binding reaction between HSA and the POM, resulting in the formation of a 1:1 complex.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Seven-year dentin bond strengths of a total- and self-etch systemEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2005Michael F. Burrow The aim of this study was to determine the durability of tensile bond strengths of a conventional 3-step bonding system (Superbond D-liner Plus) and a self-etching priming bonding system (Clearfil Liner Bond II) to bovine dentin over a 7 yr period. Superficial bovine dentin finished with 600-grit SiC paper was bonded with one of the two adhesive materials. A 4 mm diameter area was bonded, covered with resin composite and stored in 37°C deionized water containing gypsum chips and 0.4% sodium azide as an antibacterial. Bonds were stressed in tension at a crosshead speed of 1 mm min,1. Mean bond strengths were observed at 1 d, at 1, 3, and 6 months, and at 1, 2, 3, 6 and 7 yr. Ten specimens were tested for the first 3 yr and 15 specimens were tested for 6 and 7 yr. The bond strength of Superbond D-liner Plus significantly decreased over the 7 yr period, whereas Liner Bond II showed a slight but, insignificant, decrease. The fracture mode changed with time for Superbond D-liner Plus, but not for Liner Bond II. It was concluded that systems which use a strong acid for demineralizing the dentin may show greater deterioration of the bond to dentin compared with a self-etching priming system. [source] | |||||||||||||||||||||||||||||||||||||