Antimicrobial Activity of Isopteropodine

2005 ◽  
Vol 60 (5-6) ◽  
pp. 385-388 ◽  
Author(s):  
Rubén García ◽  
Cesia Cayunao ◽  
Ronny Bocic ◽  
Nadine Backhouse ◽  
Carla Delporte ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Gram Positive ◽  
Uncaria Tomentosa ◽  
Gram Positive Bacteria

Bioassay-directed fractionation for the determination of antimicrobial activity of Uncaria tomentosa, has led to the isolation of isopteropodine (0.3%), a known Uncaria pentacyclic oxindol alkaloid that exhibited antibacterial activity against Gram positive bacteria.

Antimicrobial Activity of Fractions and Compounds from Calophyllum brasiliense (Clusiaceae/Guttiferae)

2004 ◽  
Vol 59 (9-10) ◽  
pp. 657-662 ◽  
Author(s):  
Juliana B. Pretto ◽  
Valdir Cechinel-Filho ◽  
Vânia F. Noldin ◽  
Mara R. K. Sartori ◽  
Daniela E. B Isaias ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Protocatechuic Acid ◽  
Inhibitory Concentration ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Methanolic Extracts ◽  
Calophyllum Brasiliense

Abstract Calophyllum brasiliense (Clusiaceae/Guttiferae) is a native Brazilian medicinal plant traditionally used against several diseases, including infectious pathologies. Crude methanolic extracts (CME) and two fractions, denoted non-polar (soluble in chloroform) and polar (nonsoluble in chloroform), were prepared from different parts of the plant (roots, stems, leaves, flowers and fruits) and studied. The following compounds were isolated and tested against pathogenic bacteria and yeasts by determination of the minimal inhibitory concentration (MIC): brasiliensic acid (1), gallic acid (2), epicatechin (3), protocatechuic acid (4), friedelin (5) and 1,5-dihydroxyxanthone (6). The results indicated that all the parts of the plant exhibited antimicrobial activity against Gram-positive bacteria, which are selectively inhibited by components of C. brasiliense. No activity was observed against Gram-negative bacteria and yeasts tested. Regarding the isolated compounds, substance 4 showed antimicrobial activity against all the tested microorganisms, whereas compound 6 exhibited antimicrobial activity only against Gram-positive bacteria. The results from the current study confirm and justify the popular use of this plant to treat infectious processes.

Antimicrobial Capacity of Plant Polyphenols against Gram-positive Bacteria: A Comprehensive Review

2020 ◽  
Vol 27 (15) ◽  
pp. 2576-2606 ◽  
Author(s):  
Francisco Javier Álvarez-Martínez ◽  
Enrique Barrajón-Catalán ◽  
José Antonio Encinar ◽  
Juan Carlos Rodríguez-Díaz ◽  
Vicente Micol
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Mechanism Of Action ◽  
Molecular Targets ◽  
Membrane Receptors ◽  
Resistant Bacteria ◽  
Plant Polyphenols ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Promising Source

Background: Multi-drug-resistant bacteria such as Methicillin-Resistant Staphylococcus aureus (MRSA) disseminate rapidly amongst patients in healthcare facilities and suppose an increasingly important cause of community-associated infections and associated mortality. The development of effective therapeutic options against resistant bacteria is a public health priority. Plant polyphenols are structurally diverse compounds that have been used for centuries for medicinal purposes, including infections treatment and possess, not only antimicrobial activity, but also antioxidant, anti-inflammatory and anticancer activities among others. Based on the existing evidence on the polyphenols’ antibacterial capacity, polyphenols may be postulated as an alternative or complementary therapy for infectious diseases. Objective: To review the antimicrobial activity of plant polyphenols against Gram-positive bacteria, especially against S. aureus and its resistant strains. Determine the main bacterial molecular targets of polyphenols and their potential mechanism of action. Methodology: The most relevant reports on plant polyphenols’ antibacterial activity and their putative molecular targets were studied. We also performed virtual screening of thousand different polyphenols against proteins involved in the peptidoglycan biosynthesis to find potential valuable bioactive compounds. The bibliographic information used in this review was obtained from MEDLINE via PubMed. Results: Several polyphenols: phenolic acids, flavonoids (especially flavonols), tannins, lignans, stilbenes and combinations of these in botanical mixtures, have exhibited significant antibacterial activity against resistant and non-resistant Gram-positive bacteria at low μg/mL range MIC values. Their mechanism of action is quite diverse, targeting cell wall, lipid membrane, membrane receptors and ion channels, bacteria metabolites and biofilm formation. Synergic effects were also demonstrated for some combinations of polyphenols and antibiotics. Conclusion: Plant polyphenols mean a promising source of antibacterial agents, either alone or in combination with existing antibiotics, for the development of new antibiotic therapies.

Preliminary investigation of antimicrobial activity of the skin secretions of frogs from Bangladesh

2019 ◽  
Vol 40 (4) ◽  
pp. 531-536
Author(s):  
Md. Sirajul Islam ◽  
Md. Mokhlesur Rahman ◽  
Md. Mizanur Rahaman
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Preliminary Investigation ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Hoplobatrachus Tigerinus ◽  
Skin Secretions ◽  
Polypedates Leucomystax

Abstract Amphibians, like some animals and plants, defend themselves against various pathogenic organisms by producing and secreting various peptides and small molecules from granular skin glands. In this study, we evaluated for the first time, the antibiotic activity of the skin secretions of 8 different frog species (Euphlyctis cyanophlyctis, E. hexadactylus, Fejervarya teraiensis, F. asmati, F. syhadrensis, Hoplobatrachus tigerinus, Microhyla ornata and Polypedates leucomystax) from Bangladesh. These secretions were collected by a nonlethal approach through chemical stimulation and the antibacterial activity was evaluated by broth macrodilution method against some Gram-positive and Gram-negative bacteria. Our study revealed that all the skin secretions (8 out of 8) from the selected frogs have antimicrobial activity against Gram-positive bacteria and 7 out of 8 skin secretions possess antibacterial activity against Gram-negative bacteria tested. Further analysis of data showed that these secretions are significantly more effective against Gram-positive bacteria than Gram-negative bacteria.

scholarly journals DETERMINATION OF ANTIBACTERIAL ACTIVITY OF SOME IMPORTANT SPICES

2015 ◽  
Vol 3 (10) ◽  
pp. 57-64
Author(s):  
Ranganathan Kapilan
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Maximum Activity ◽  
Gram Negative Bacteria ◽  
Alcoholic Extract ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Wide Range

Wide range of plant extracts are used for medicinal purposes as they are very cheap, efficient, harmless and do not cause any side effects. Spices are parts of different plants and they add special aroma and taste to the food preparations. The aim of the study was to determine the antimicrobial activity of some important naturally grown spices against gram positive and gram negative pathogenic bacteria. Antibacterial activity of the spices was tested against gram positive bacteria Bacillus pumilus, Bacillus cereus and Staphylococcus aureus and gram negative bacteria Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa using aqueous, ethanolic, methanolic and liquid nutrient extracts. Among all the extracts tested alcoholic extracts of Cardamom (Elettaria cardamom), clove (Eugenia caryophyllus) and lemongrass (Cymbopogoncitratus) showed maximum antimicrobial activity against gram negative bacteria while alcoholic extract of Cardamom (Elettaria cardamom) and lemongrass (Cymbopogoncitratus) showed maximum activity against gram positive bacteria. All the spices tested in this study proved that they have antibacterial activity and the maximum activity index (1.39) was exhibited by the ethanol extract of cardamom against E.coli.

Activity Retention after Nisin Entrapment in a Polyethylene Oxide Brush Layer

2014 ◽  
Vol 77 (9) ◽  
pp. 1624-1629 ◽  
Author(s):  
JULIE A. AUXIER ◽  
KARL F. SCHILKE ◽  
JOSEPH McGUIRE
Keyword(s):  
Antimicrobial Activity ◽  
Polyethylene Oxide ◽  
Food Packaging ◽  
Indicator Strain ◽  
Small Peptides ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Coated Surfaces ◽  
Nisin Activity

The cationic, amphiphilic peptide nisin is an effective inhibitor of gram-positive bacteria whose mode of action does not encourage pathogenic resistance, and its proper incorporation into food packaging could enhance food stability, safety, and quality in a number of circumstances. Sufficiently small peptides have been shown to integrate into otherwise nonfouling polyethylene oxide (PEO) brush layers in accordance with their amphiphilicity and ordered structure, including nisin, and we have recently shown that nisin entrapment within a PEO layer does not compromise the nonfouling character of that layer. In this work we test the hypothesis that surface-bound, pendant PEO chains will inhibit displacement of entrapped nisin by competing proteins and, in this way, prolong retention of nisin activity at the interface. For this purpose, the antimicrobial activity of nisin-loaded, PEO-coated surfaces was evaluated against the gram-positive indicator strain, Pediococcus pentosaceous. The retained antimicrobial activity of nisin layers was evaluated on uncoated and PEO-coated surfaces after incubation in the presence of bovine serum albumin for contact periods up to 1 week. Nisin-loaded, uncoated and PEO-coated samples were withdrawn at selected times and were incubated on plates inoculated with P. pentosaceous to quantify nisin activity by determination of kill zone radii. Our results indicate that nisin activity is retained at a higher level for a longer period of time after entrapment within PEO than after direct adsorption in the absence of PEO, owing to inhibition of nisin exchange with dissolved protein afforded by the pendant PEO chains.

scholarly journals Antimicrobial activity and thiosulfinates profile of a formulation based on Allium cepa L. extract

2017 ◽  
Vol 15 (1) ◽  
pp. 175-181
Author(s):  
O. Orăşan ◽  
R. Oprean ◽  
A. Saplonţai-Pop ◽  
M. Filip ◽  
R. Carpa ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Allium Cepa ◽  
High Performance ◽  
Ultrapure Water ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Liquid Extract ◽  
Allium Cepa L

AbstractBackgroundAllium species extracts including Allium cepa L. contain sulfur compounds, known for their antiplatelet, antimicrobial, antineoplasic activities.MethodologyAntibacterial activity of a formulation based on A. cepa extracts-liquid and lyophilized samples, has been demonstrated using two classes of bacteria: Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) and three methods: discs soaked with liquid extract, the wells method in the culture medium, filled with the liquid extract and lyophilized formulation extracts transformed by the incorporation of ultrapure water. The second part of this study includes identification of thiosulfinates compounds from the studied samples by high performance liquid chromatography - mass spectrometry (HPLC-MS).ResultsThe most important inhibition and the highest antibacterial effficiency were observed against Gram-positive bacteria, such as Staphylococcus aureus. The HPLC-MS thiosulfinates profile of the tested formulation extracts shows the presence of seven thiosulfinate compounds, MeS(O)S 1-propenyl (E,Z); n-PrS(O)S 1-propenyl-(E); n-PrS(O)S 1-propenyl-(Z); trans-zwiebelane; n-PrS(O)CHEtSS-1propenyl; 1-propenylS(O)CHEtSS1-propenyl, which may be responsible for antibacterial activity.ConclusionTesting antimicrobial effects using the three mentioned methods confirmed the antimicrobial activity of the tested samples based on A. cepa extracts, with a demonstrated content of seven thiosulfinate compounds.

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

scholarly journals A novel bis(pyrazolyl)methane compound as a potential agent against Gram-positive bacteria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pedro Seguí ◽  
John J. Aguilera-Correa ◽  
Elena Domínguez-Jurado ◽  
Christian M. Sánchez-López ◽  
Ramón Pérez-Tanoira ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Effect ◽  
Eukaryotic Cell ◽  
Liver Carcinoma ◽  
Gram Positive ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Therapeutic Compounds ◽  
Toxic Concentrations

AbstractThis study was designed to propose alternative therapeutic compounds to fight against bacterial pathogens. Thus, a library of nitrogen-based compounds bis(triazolyl)methane (1T–7T) and bis(pyrazolyl)methane (1P–11P) was synthesised following previously reported methodologies and their antibacterial activity was tested using the collection strains of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Moreover, the novel compound 2P was fully characterized by IR, UV–Vis and NMR spectroscopy. To evaluate antibacterial activity, minimal inhibitory concentrations (MICs), minimal bactericidal concentrations (MBCs), minimum biofilm inhibitory concentrations (MBICs), and minimum biofilm eradication concentrations (MBECs) assays were carried out at different concentrations (2–2000 µg/mL). The MTT assay and Resazurin viability assays were performed in both human liver carcinoma HepG2 and human colorectal adenocarcinoma Caco-2 cell lines at 48 h. Of all the synthesised compounds, 2P had an inhibitory effect on Gram-positive strains, especially against S. aureus. The MIC and MBC of 2P were 62.5 and 2000 µg/mL against S. aureus, and 250 and 2000 µg/mL against E. faecalis, respectively. However, these values were > 2000 µg/mL against E. coli and P. aeruginosa. In addition, the MBICs and MBECs of 2P against S. aureus were 125 and > 2000 µg/mL, respectively, whereas these values were > 2000 µg/mL against E. faecalis, E. coli, and P. aeruginosa. On the other hand, concentrations up to 250 µg/mL of 2P were non-toxic doses for eukaryotic cell cultures. Thus, according to the obtained results, the 2P nitrogen-based compound showed a promising anti-Gram-positive effect (especially against S. aureus) both on planktonic state and biofilm, at non-toxic concentrations.

Preparation of bioactive and antibacterial PMMA-based bone cement by modification with quaternary ammonium and alkoxysilane

2021 ◽  
pp. 088532822110044
Author(s):  
Haiyang Wang ◽  
Toshinari Maeda ◽  
Toshiki Miyazaki
Keyword(s):  
Antibacterial Activity ◽  
Methyl Methacrylate ◽  
Bone Cement ◽  
Setting Time ◽  
Antibacterial Properties ◽  
The Body ◽  
Apatite Formation ◽  
Gram Positive ◽  
E Coli ◽  
Gram Positive Bacteria

Bone cement based on poly(methyl methacrylate) (PMMA) powder and methyl methacrylate (MMA) liquid is a very popular biomaterial used for the fixation of artificial joints. However, there is a risk of this cement loosening from bone because of a lack of bone-bonding bioactivity. Apatite formation in the body environment is a prerequisite for cement bioactivity. Additionally, suppression of infection during implantation is required for bone cements to be successfully introduced into the human body. In this study, we modified PMMA cement with γ-methacryloxypropyltrimetoxysilane and calcium acetate to introduce bioactive properties and 2-( tert-butylamino)ethyl methacrylate (TBAEMA) to provide antibacterial properties. The long-term antibacterial activity is attributed to the copolymerization of TBAEMA and MMA. As the TBAEMA content increased, the setting time increased and the compressive strength decreased. After soaking in simulated body fluid, an apatite layer was detected within 7 days, irrespective of the TBAEMA content. The cement showed better antibacterial activity against Gram-negative E. Coli than Gram-positive bacteria; however, of the Gram-positive bacteria investigated, B. subtilis was more susceptible than S. aureus.

scholarly journals Enaminone-Derived Pyrazoles with Antimicrobial Activity

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mashooq Ahmad Bhat ◽  
Mohamed A. Al-Omar ◽  
Ahmed M. Naglah ◽  
Abdul Arif Khan
Keyword(s):  
Antimicrobial Activity ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
Disc Diffusion ◽  
Initial Screening ◽  
Gram Positive ◽  
Gram Negative ◽  
Disc Diffusion Assay ◽  
Gram Positive Bacteria ◽  
Diffusion Assay

A series of pyrazoles derived from the substituted enaminones were synthesized and were evaluated for antimicrobial activity. All the compounds were characterized by the spectral data and elemental analysis. The synthesized compounds were initially screened for their antimicrobial activity against ATCC 6538, NCTC 10400, NCTC 10418, and ATCC 27853. During initial screening, compounds (P1, P6, and P11) presented significant antimicrobial activity through disc diffusion assay. These compounds were further evaluated for antimicrobial activity at different time points against Gram-positive and Gram-negative bacteria and presented significant activity for 6 hours. The activity was found to be greater against Gram-positive bacteria. In contrast at 24 hours, the activity was found only against Gram-positive bacteria except compound (P11), showing activity against both types of bacteria. Compound (P11) was found to have highest activity against both Gram-positive and Gram-negative bacteria.

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