Search results

1

Synthesis, antiprotozoal and antibacterial activity of nitro- and halogeno-substituted benzimidazole derivatives.

100%

Kazimierczuk Z., Upcroft J. A., Upcroft P., Górska A., Starościak B., Laudy A.

|

2002

|

vol. 49

|

issue 1

185-195

EN

Two series of benzimidazole derivatives were sythesised. The first one was based on 5,6-dinitrobenzimidazole, the second one comprises 2-thioalkyl- and thioaryl-substituted modified benzimidazoles. Antibacterial and antiprotozoal activity of the newly obtained compounds was studied. Some thioalkyl derivatives showed remarkable activity against nosocomial strains of Stenotrophomonas malthophilia, and an activity comparable to that of metronidazole against Gram-positive and Gram-negative bacteria. Of the tested compounds, 5,6-dichloro-2-(4-nitrobenzylthio)-benzimidazole showed the most distinct antiprotozoal activity.

2

Nanosilver - does it have only one face?

100%

Likus W., Bajor G., Siemianowicz K.

|

2013

|

vol. 60

|

issue 4

495-501

EN

Silver nanoparticles (NPs) have at least one dimension of a particle smaller than 100 nm and contain 20-15,000 silver atoms. Due to its antibacterial activity nanosilver (NS) is used for medical purposes. NS particles can be obtained by various methods. Potentially, the best method of the NS synthesis for medical purposes is based on a brief flow of electric current between two silver electrodes placed in deionized water. It is accepted that the major antibacterial effect of silver is its partial oxidation and releasing silver ions, which interact with thiol groups of peptidoglicans of bacterial cell wall, and proteins of the cell membrane causing cell lysis. Silver ions can also bind to bacterial DNA preventing its replication and stopping synthesis of bacterial proteins. The rise in exposure to silver NPs has spurred interest into their toxicology. NS undergoes a set of biochemical transformations including accelerated oxidative dissolution in gastric acid, binding to thiol groups of serum and tissue proteins, exchange between thiol groups, sulfides and selenides, binding to selenoproroteins and photoreduction in skin to zerovalent metallic silver. Animal studies have shown that exposure to NS may lead to liver and spleen damage. NS can also stimulate an increased secretion of proinflammatory cytokines by monocytes. As a spectrum of NS applications is still growing, the complex evaluation of a safety of its use becomes an important task. This requires an elucidation of not only the influence of NS on human cells and organism, but also its biotransformation in organism and in environment.

3

FORMATION AND PROPERTIES OF DBC/PLA MICROFIBRES

88%

Biniaś D., Biniaś W., Machnicka A., Janicki J., Hałuszka P.

Progress on Chemistry and Application of Chitin and its Derivatives

|

2017

|

vol. 22

5-13

EN

In this study, a solution of dibutyrylchitin (DBC)/polylactide (PLA) blend micro and nanofibres were successfully fabricated using blends of 2,2,2-trifluoroethanol (TFE) as solvents. Fibres were produced from the solutions by electrospinning. The DBC/PLA blend solutions in various ratios were studied for electrospinning into micro/nanofibres. The morphology of the micro and nanofibres was observed by scanning electron microscope (SEM). The biggest diameters of DBC/PLA fibres were obtained for the blended microfibres in ratios of 10/90 and 25/75. The smallest diameter was observed for pure polymers. The antibacterial properties were examined for materials obtained by electrospinning. In the experiments, materials with antibacterial properties were made. It is likely that the electrospun micro and nanofibres will be used in the native extracellular matrix for tissue engineering.

4

In vitro pharmacological interaction of caffeine and first-line antibiotics is antagonistic against clinically important bacterial pathogens

88%

Olajuyigbe O., Adeoye-Isijola M., Okon V., Adedayo O., Coopoosamy R.

|

2017

|

vol. 64

|

issue 2

255-263

EN

The in vitro antibacterial activity of pure caffeine powder and its interaction with first line antibiotic against bacterial isolates were investigated with the macrobroth dilution and the checkerboard assay methods. This study showed that caffeine and the antibiotics exhibited various degrees of antibacterial activities. While caffeine had MICs ranging between 67.19 and 268.75 µg/ml, chloramphenicol was characterized by MICs between 0.98 and 31.25 µg/ml, kanamycin - 15.63-62.5 µg/ml, nalidixic acid - 0.49-250 µg/ml, erythromycin - 0.49-62.5 µg/ml, tetracycline - 1.99-62.5 µg/ml and metronidazole - 15.63-31.25 µg/ml. Combining ½ MICs and MICs of caffeine with the antibiotics as well as direct combination of caffeine and the antibiotics resulted in significant reduction of antibiotics' effectiveness. The fractional inhibitory concentration index (FICI) for the combination of ½ MICs of caffeine with different antibiotics showed antagonistic interactions with the antibiotics except kanamycin which had additive and indifferent interactions with caffeine. The FICI of the MICs of caffeine combined with antibiotics showed a reduction in the number of antagonistic interactions as chloramphenicol, nalidixic acid and erythromycin showed some indifferent interactions while kanamycin was the only antibiotic that showed indifferent interaction against all the bacterial isolates. The direct combination of caffeine and the antibiotics resulted in significant antagonistic interactions higher than in the case when caffeine, at the ½ MICs and MICs, was combined with the antibiotics. Although caffeine demonstrated significant antibacterial activity against the selected bacterial isolates, its combination with the selected antibiotics resulted in significant antagonistic interactions. Caffeine should not be combined with antibiotics as this could result in serious therapeutic failure and, possibly, drug toxicity in vivo.

5

Supercritical carbon dioxide hops extracts with antimicrobial properties

88%

Rój E., Tadić V. M., Mišić D., Žižović I., Arsić I., Dobrzyńska-Inger A., Kostrzewa D.

Open Chemistry

|

2015

|

vol. 13

|

issue 1

EN

Extracts obtained from hops (Humulus lupulus L., Cannabaceae) by supercritical fluid extraction (SFE), SFE followed by isomerization, as well as by conventional technique, were investigated for their chemical composition and antibacterial activity against selected foodborne pathogens and microorganisms capable to cause the food spoilage. The antibacterial activity of the extracts was compared with the antibacterial activity of xanthohumol, compound known for its broad pharmacological properties, isolated from the raw material remained after the SFE. Xanthohumol (XH, 96%) proved to posses the most prominent activity against all the tested strains, with the MIC values ranged between 2.5 and 20 μg mL-1. Supercritical hops extract and potassium isomerized supercritical hops extract showed strong antibacterial activity against the tested strains as well. Escherichia coli was not affected by the extracts, meaning that their oral admission would not cause the same problem as antibiotic application in intestinal flora. The chemical composition of the investigated hops extracts was analysed by GC-MS. Contents of α-acids, β-acids, iso-α-acids and xanthohumol in the samples were determined by HPLC.

6

The involvement of protein kinase A in the immune response of Galleria mellonella larvae to bacteria

88%

Cytryńska M., Zdybicka-Barabas A., Jakubowicz T.

|

2007

|

vol. 54

|

issue 1

167-174

EN

The role of protein kinase A (PKA) in the humoral immune response of the greater wax moth Galleria mellonella larvae to live Gram-positive bacteria Micrococcus lysodeikticus and Gram-negative bacteria Escherichia coli was investigated. The immune challenge of larvae with both kinds of bacteria caused an increase in fat body PKA activity depending on the injected bacteria. Gram-positive M. lysodeikticus was a much better inducer of the enzyme activity than Gram-negative E. coli. The PKA activity was increased about 2.5-fold and 1.5-fold, after M. lysodeikticus and E. coli injection, respectively. The in vivo inhibition of the enzyme activity by a cell permeable selective PKA inhibitor, Rp-8-Br-cAMPS, was correlated with considerable changes of fat body lysozyme content and hemolymph antimicrobial activity in bacteria-challenged insects. The kinetics of changes were different and dependent on the bacteria used for the immune challenge of G. mellonella larvae.

7

Biological activities and chemical composition of solvent extracts of Stoechospermum marginatum (C. Agardh)

88%

Esmaeili A., Khakpoor M.

|

2012

|

vol. 59

|

issue 4

581-585

EN

The objective of this study was to evaluate the chemical composition CH3OH-CH2Cl2 (1:1) extract and biological activities of various extracts derived from the aerial parts of the brown marine alga Stoechospermum marginatum (C. Agardh). Gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS) were used to analyze the composition of the essential oil. Total phenolics assay demonstrated a high value in hexane extract (HE), with a lower value for chloroform extract (CE), and the lowest value for methanol extract (ME). DPPH (2,2-diphenyl-1-picrylhydrazyl) assay showed that extracts of S. marginatum possess radical scavenging activity (RSA). Tests of the antioxidant property of the extracts revealed both electron and hydrogen transfer mechanisms. The antibacterial activity of the ME, CE, and HE as well as an ethanol extract was estimated against seven Gram-positive and Gram-negative bacteria. The ethanol extract showed the highest antibacterial activity, and the HE showed the lowest.

8

Antibacterial effects of hydrogen peroxide and caprylic acid on selected foodborne bacteria

88%

Výrostková J., Pipová M., Semjon B., Jevinová P., Regecová I., Maľová J., Výrostková J., Pipová M., Semjon B., Jevinová P., Regecová I., Maľová J.

Polish Journal of Veterinary Sciences

|

2020

|

vol. 23

|

issue 3

9

Facile synthesis of chitosan/CuO nanocomposites for potential use as biocontrol agents

75%

Siriphannon P., Iamphaojeen Y.

|

2018

|

issue 3

10

Chemical profile and antibacterial activity of essential oils from leaves and fruits of Gaultheria procumbens L. cultivated in Poland

75%

Magiera A., Sienkiewicz M., Olszewska M., Kicel A., Michel P.

Acta Poloniae Pharmaceutica - Drug Research

|

2019

|

vol. 76

|

issue 1

93-102

EN

Essential oils (EOs) of Gaultheria procumbens were obtained by hydrodistillation with the yield of 1.30% ± 0.05 (v/dw) for leaves and 2.68% ± 0.08 (v/dw) for fruits. The GC-FID/MS analysis led to the identification of 64 volatile components, among which 27 were found in leaf EO, 49 in fruit EO, and 59 analytes were detected for the first time in G. procumbens. Methyl salicylate, which is known as a potent anti-inflammatory agent, was the dominant component making up to 97.5% and 99.8% of the total fruit and leaf EOs, respectively. The remaining volatiles of the leaves included mainly monoterpenes (α-pinene, β-pinene, limonene), methyl-o-anisate, massoilactone, spiro[4,5]decane-1-one, and aliphatic alcohols (heptan-2-ol, octan-1-ol), while the fruit EO contained apart from the dominant aliphatic and aromatic alcohols (benzyl alcohol, heptan-2-ol, p-cymen-7-ol) also carboxylic acids (3-hydroxyphenylacetic acid, heptanoic acid, octanoic acid) and aldehydes (hexanal, furfural, pent-4-enal). The antibacterial activity of the EOs was evaluated using a microdilution broth method against twelve reference strains, as well as clinical and environmental isolates. Differences between activity parameters of both EOs were not statistically significant (p > 0.05) for most tested bacteria. On the other hand, both EOs were significantly more effective against Gram-negative (MIC, 8.2-10.0 mg/mL) than Gram-positive bacteria (MIC, 13.5-16.7 mg/mL). Leaves and especially fruits of G. procumbens cultivated in Poland were proved valuable sources of methyl salicylate-rich EOs of moderate antibacterial activity, which, therefore, could partly explain the traditional use of the plant materials and the EOs in the treatment of bacterial infections-related inflammatory disorders.

11

GC-MS Analysis and Biological activity of Essential Oil of Fruits, Needles and Bark of Pinus pinea grown wildly in Jordan

75%

Halloum B., Shakya A. K., Elagbar Z. A., Naik R. R.

Acta Poloniae Pharmaceutica - Drug Research

|

2019

|

vol. 76

|

issue 5

825-831

EN

Essential oils from needles, fruits and bark was extracted from Pinus pinea L. (stone pine) grown wildly in Jordan. The chemical composition, antibacterial activity, antioxidant activity of essential oils was evaluated. The chemical compositions were identified using Gas-Chromatography-Mass spectrometry (GC-MS) and retention Indices (Van den Dool & Kratz). The results show that the essential oil obtained from needles composed mainly of Guaiol (12.7%), limonene (11.42%), and β-caryophyllene (7.61%), while fruit contains limonene (32.56%), and α-pinene (6.78%). The essential oils from barks were rich in β-caryophyllene (16.51%), limonene (14.83%), caryophyllene oxide (11.83%), and longifolene (7.51%). In vitro, antibacterial activity of the essential oil samples was evaluated using agar-well diffusion method against three different strains of bacteria (Gram¬-positive bacteria: Staphylococcus aureus and Gram-negative bacteria: Klebsiella pneumoniae and Escherichia coli). The results showed that essential oil showed appreciable antibacterial activity against S. aureus. The essential oil from fruit exhibited weak antibacterial activity against E. coli and K. pneumoniae. Essential oils of P. pinea showed appreciable antioxidant activity in-vitro.

12

Antibacterial activity of caffeine against plant pathogenic bacteria

75%

Sledz W., Los E., Paczek A., Rischka J., Motyka A., Zoledowska S., Piosik J., Lojkowska E.

|

2015

|

vol. 62

|

issue 3

605-612

EN

The objective of the present study was to evaluate the antibacterial properties of a plant secondary metabolite - caffeine. Caffeine is present in over 100 plant species. Antibacterial activity of caffeine was examined against the following plant-pathogenic bacteria: Ralstonia solanacearum (Rsol), Clavibacter michiganesis subsp. sepedonicus (Cms), Dickeya solani (Dsol), Pectobacterium atrosepticum (Pba), Pectobacterium carotovorum subsp. carotovorum (Pcc), Pseudomonas syringae pv. tomato (Pst), and Xanthomonas campestris subsp. campestris (Xcc). MIC and MBC values ranged from 5 to 20 mM and from 43 to 100 mM, respectively. Caffeine increased the bacterial generation time of all tested species and caused changes in cell morphology. The influence of caffeine on the synthesis of DNA, RNA and proteins was investigated in cultures of plant pathogenic bacteria with labelled precursors: [3H]thymidine, [3H]uridine or 14C leucine, respectively. RNA biosynthesis was more affected than DNA or protein biosynthesis in bacterial cells treated with caffeine. Treatment of Pba with caffeine for 336 h did not induce resistance to this compound. Caffeine application reduced disease symptoms caused by Dsol on chicory leaves, potato slices, and whole potato tubers. The data presented indicate caffeine as a potential tool for the control of diseases caused by plant-pathogenic bacteria, especially under storage conditions.

13

Solid Fly-ash:PTS catalyzed synthesis, spectral studies and antimicrobial activities of some 1,3-diarylpropenones

63%

Arulkumarana R., Vanangamudia G., Kamalakkannana D., Sundararajana R., Vijayakumara S., Thirumurthyb K., Mayavelb P., Thirunarayanan G.

|

2012

|

vol. 67

|

issue 1-2

45-77

EN

The green catalyst Fly-ash:PTS has been prepared and characterized by IR and SEM analysis. Using this catalyst some aryl chalcones have been synthesized by aldol condensation of aryl methyl ketone and substituted benzaldehydes. It has been observed that this reaction yields more than 85% of the product. These chalcones have been characterized by their physical constants and spectral data following the procedures published in literature. The effect of substituents on the spectral data of the chalcones, synthesized, has been studied using single and multi-regression analysis with Hammett equation. The antibacterial and antifungal activities of these chalcones have been studied using Bauer-Kirby method.

Refine search results

Synthesis, antiprotozoal and antibacterial activity of nitro- and halogeno-substituted benzimidazole derivatives.

Nanosilver - does it have only one face?

FORMATION AND PROPERTIES OF DBC/PLA MICROFIBRES

In vitro pharmacological interaction of caffeine and first-line antibiotics is antagonistic against clinically important bacterial pathogens

Supercritical carbon dioxide hops extracts with antimicrobial properties

The involvement of protein kinase A in the immune response of Galleria mellonella larvae to bacteria

Biological activities and chemical composition of solvent extracts of Stoechospermum marginatum (C. Agardh)

Antibacterial effects of hydrogen peroxide and caprylic acid on selected foodborne bacteria

Facile synthesis of chitosan/CuO nanocomposites for potential use as biocontrol agents

Chemical profile and antibacterial activity of essential oils from leaves and fruits of Gaultheria procumbens L. cultivated in Poland

GC-MS Analysis and Biological activity of Essential Oil of Fruits, Needles and Bark of Pinus pinea grown wildly in Jordan

Antibacterial activity of caffeine against plant pathogenic bacteria

Solid Fly-ash:PTS catalyzed synthesis, spectral studies and antimicrobial activities of some 1,3-diarylpropenones