scholarly journals Characterization, Antimicrobial Properties and Coatings Application of Gellan Gum Oxidized with Hydrogen Peroxide

Foods ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 31 ◽  
Author(s):  
Yushuang Lu ◽  
Xiaojian Zhao ◽  
Sheng Fang
Keyword(s):  
Hydrogen Peroxide ◽  
1H Nmr Spectroscopy ◽  
Antimicrobial Properties ◽  
Antimicrobial Activities ◽  
Gellan Gum ◽  
Proton Nuclear Magnetic Resonance ◽  
Carboxyl Groups ◽  
Gram Negative Bacteria ◽  
Gram Positive Bacteria ◽  
H2o2 Oxidation

The effect of hydrogen peroxide (H2O2) oxidation on the physicochemical, gelation and antimicrobial properties of gellan gum was studied. The oxidized gellan gum (OGG) was characterized by measuring the carboxyl/carbonyl group contents, Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The H2O2 oxidation resulted in a large increase in the carboxyl groups in gellan gum. The OGG lost gelation ability by oxidation even in the presence of metal ions. The antimicrobial activities of the OGG against Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and fungal (Aspergillus niger) were tested. The OGG could inhibit the growth of both bacteria and fungal, and the activity was improved with an increase in the oxidation level. Finally, the application of the OGG as an active coatings material to extend the storage of apples was tested.

scholarly journals Studies on bioactive bis-1,3,5-triazinyl dithiocarbamates

2007 ◽  
Vol 72 (7) ◽  
pp. 635-641 ◽  
Author(s):  
V.D. Lunagariya ◽  
R.M. Desai ◽  
V.H. Shah
Keyword(s):  
Antimicrobial Activity ◽  
Nmr Spectroscopy ◽  
1H Nmr Spectroscopy ◽  
Antimicrobial Activities ◽  
Gram Negative Bacteria ◽  
Plate Method ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Elemental Analyses ◽  
Bacteria And Fungi

The compounds bis(4,6-dichloro/bis[(p-methoxyphenyl)amino]-1,3,5- -triazin-2-yl)1,2-hydrazine-1,2-dicarbodithioate/1,4-phenylenebis(carbamodithioate)/( 1,1?-biphenyl)-4,4?-diylbis(carbamodithioate)/(sulphonyldi-4,1-phenylene)- bis(carbamodithioate/1,2-ethanediylbis(carbamothioate) 4a-j were synthesized by two different methods. In the first method (A) for the preparation of 4a-e, 2,4,6- trichloro-1,3,5-triazine 1 was condensed with diammonium 1,2-hydrazine-1,2-dicarbodithioate/ 1,4-phenylenebis(carbamodithioate)/(1,1?-biphenyl)-4,4?diylbis(carbamodithioate)/( sulphonyl-di-4,1-phenylene)-bis(carbamodithioate)/1,2-ethanediylbis(carbamodithioate) 3a-e to afford 4a-e which undergo reaction with p-methoxyaniline to afford 4f-j. In the second method (B) of preparation, 1 was condensed with p-methoxyaniline to yield 2 followed by the action of 3a-e to yield 4a-j. The structure of the newly synthesized compounds 4a-j was established on the basis of elemental analyses, as well as IR and 1H-NMR spectroscopy. The antimicrobial activities of compounds 4a-j were determined by the cup-plate method against gram-positive bacteria, gram-negative bacteria and fungi. All the synthesized compounds showed significant antimicrobial activity.

scholarly journals Antimicrobial Activities of Mefloquine and a Series of Related Compounds

2000 ◽  
Vol 44 (4) ◽  
pp. 848-852 ◽  
Author(s):  
C. M. Kunin ◽  
W. Y. Ellis
Keyword(s):  
Staphylococcus Epidermidis ◽  
Antimicrobial Activities ◽  
Walter Reed Army Institute ◽  
Gram Negative Bacteria ◽  
Antimicrobial Drugs ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
Related Compounds

ABSTRACT Mefloquine was found to have bactericidal activity against methicillin- and fluoroquinolone-susceptible and -resistant strains ofStaphylococcus aureus and Staphylococcus epidermidis and gentamicin- and vancomycin-resistant strains ofEnterococcus faecalis and Enterococcus faecium. The MICs were 16 μg/ml, and the minimal bactericidal concentrations (MBCs) were 16 to 32 μg/ml. These concentrations cannot be achieved in serum. Mefloquine was active at a more achievable concentration against penicillin-susceptible and -resistant Streptococcus pneumoniae, with MICs of 0.2 to 1.5 μg/ml. Mefloquine was not active against gram-negative bacteria and yeasts. In an attempt to find more active derivatives, 400 mefloquine-related compounds were selected from the chemical inventory of The Walter Reed Army Institute of Research. We identified a series of compounds containing a piperidine methanol group attached to pyridine, quinoline, and benzylquinoline ring systems. These had activities similar to that of mefloquine against S. pneumoniae but were far more active against other gram-positive bacteria (MICs for staphylococci, 0.8 to 6.3 μg/ml). They had activities similar to that of amphotericin B againstCandida spp. and Cryptococcus neoformans. Combinations of the compounds with gentamicin and vancomycin were additive against staphylococci and pneumococci. The MIC and MBC of gentamicin were decreased by four- to eightfold when this drug was combined with limiting dilutions of the compounds. There was no antagonism with other antimicrobial drugs. The compounds were rapidly bactericidal. They appear to act by disrupting cell membranes. Combinations of the compounds with aminoglycoside antibiotics may have potential for therapeutic use.

scholarly journals Chemical Composition, Antimicrobial, Cytotoxic and Antiplasmodial Activities of Three Sponges from Buton Islands, Indonesia

2017 ◽  
Vol 22 (3) ◽  
pp. 147
Author(s):  
Masteria Yunovilsa Putra ◽  
Tri Aryono Hadi
Keyword(s):  
Fungal Pathogen ◽  
Brine Shrimp ◽  
Antimicrobial Activities ◽  
Marine Sponges ◽  
Sponge Species ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
Gram Positive Bacteria ◽  
Ms Analysis ◽  
Inhibition Zones

GC-MS analysis of the crude extracts of three different species of Indonesian marine sponges has been carried out for identification of bioactive compounds. The GC-MS analysis from Haliclona (Gellius) sp., Lamellodysidea herbacea, and Spheciospongia inconstans revealed the presence of 23, 21, 19 various compounds, respectively and mainly sterols and fatty acids. All the sponge species has been evaluated for antimicrobial activities, cytotoxicity using brine shrimp lethality bioassay and heme polymerization inhibitory activity assay for antiplasmodial activity. In this study, all the sponge species showed antimicrobial activities against at leastone of the test strains. Among them, the extract of sponge Lamellodysidea herbacea displayed activity against two Gram-positive bacteria (S. aureus and B. subtilis) and the Gram-negative bacteria V. cholerae, with inhibition zones of 10.3, 9.2 and 9.5 mm, respectively. The sponge Haliclona (Gellius) sp., showed significant activity against fungal pathogen C. albicans. The sponge Haliclona (Gellius) sp., displayed the ability to inhibit heme polymerization indicating an anti-Plasmodium function and also showed potent cytotoxic activity against the brine shrimp Artemia sp. Keywords: GC-MS analysis, antimicrobial, sponges,bioactive

scholarly journals Synthesis and Bioassay of Novel Quinozolins

2019 ◽  
Vol 17 (72) ◽  
pp. 129-138
Author(s):  
Yasmine Kadom. Al-Majedy
Keyword(s):  
Twist Angle ◽  
Antimicrobial Properties ◽  
Heat Of Formation ◽  
Gram Negative Bacteria ◽  
The Novel ◽  
Gram Positive Bacteria ◽  
Visible Spectra ◽  
Ft Ir ◽  
Uv Visible

Novel Quinozolins were synthesized in a good yield through convert lacton to lactam and study the biological activity of the synthesized compounds. Quinozolins were characterized by elemental analysis, FT-IR and UV/visible spectra. The novel Quinozolins have been tested in vitro against (gram positive bacteria Staphylococcus aureus and against other gram negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus vulgaris; in order to assess their antimicrobial properties. Moreover, charge, bond length, bond angle, twist angle, heat of formation and steric energy were calculated by using of the ChemOffice program. The study indicates that these Quinozolins have high activity against tested bacteria. Based on the reported results, it may be concluded that the coumarin act as synthons for synthesis of new Quinozolins derivatives through the replacement of oxygen atom by nitrogen atom.

ANTIMICROBIAL ACTIVITY OF A MONOALKYL BENZENE SULPHONATE COMPLEX

1962 ◽  
Vol 8 (5) ◽  
pp. 621-628 ◽  
Author(s):  
W. A. Taber ◽  
B. B. Wiley
Keyword(s):  
Active Component ◽  
Fusarium Species ◽  
Antimicrobial Activities ◽  
Gram Negative Bacteria ◽  
Fusarium Spp ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Household Detergent ◽  
Fungi Imperfecti

The antimicrobial activities of a branched, monoalkyl benzene sulphonate complex (ABS), the active component of a commercial liquid household detergent, and of the detergent have been investigated. Cultures of dermatophytes, Candida albicans, saprophytic phycomycetes, ascomycetes, fungi imperfecti, Gram-positive and Gram-negative bacteria were tested. Only the Fusarium species and the Gram-negative bacteria were not inhibited by a concentration of 0.1 ml of the detergent/50 ml medium. Microgram quantities of ABS inhibited the Gram-positive bacteria and the fungi except Fusarium spp. ABS was lethal in microgram quantities, the effect being detectable within 30 minutes. Inhibition of exogenous respiration of glucose by C. albicans began upon contact and was complete within 50 minutes. A linear and biodegradable ABS was more active than the branched form against C. albicans.

scholarly journals Equilibria in Aqueous Cobalt(II)—Reduced Schiff Base N-(2-hydroxybenzyl)alanine System: Chemical Characterization, Kinetic Analysis, Antimicrobial and Cytotoxic Properties

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3462
Author(s):  
Magdalena Woźniczka ◽  
Manas Sutradhar ◽  
Armando J. L. Pombeiro ◽  
Mirosława Świątek ◽  
Marek Pająk ◽  
...  
Keyword(s):  
Schiff Base ◽  
Kinetic Analysis ◽  
Staphylococcus Epidermidis ◽  
Antimicrobial Properties ◽  
Chemical Characterization ◽  
Point Of View ◽  
Gram Negative Bacteria ◽  
Gram Positive Bacteria ◽  
Mononuclear Complexes ◽  
Reduced Schiff Base

The present study describes the coordination properties of a reduced Schiff base, N-(2-hydroxybenzyl)alanine, towards cobalt(II) using potentiometric as well as spectroscopic (UV-Vis and ESI-MS) methods. The results indicate the formation of six mononuclear complexes showing high stability in aqueous solution. Coordination occurs in the {O−phenolic,N,O−carboxyl} and {N,O−carboxyl} chelation modes, depending on the degree of ligand deprotonation. Examination of the complexation equilibria at pH ca 7, which is important from a biological point of view, allowed to identify two species: [CoL] and [CoL2H]−. The kinetic analysis showed a structural change of those cobalt(II) complexes from octahedral to tetrahedral in accordance with a first-order time relationship. The antimicrobial properties of N-(2-hydroxybenzyl)alanine, cobalt(II) nitrate and of the Co(II) – ligand complexes were determined against Gram-positive bacteria (Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis), Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Helicobacter pylori) and a fungal strain (Candida). The results indicate that the complexes are more active for more strains than the ligand alone. Nevertheless, the complexes induce a higher decrease in the metabolic activity of cells but without damage to nuclei. Tetrahedral structures show stronger anti-cellular toxicity than octahedral complexes, which is most likely due to the higher accessibility of the cobalt(II) center.

scholarly journals In Vitro Antimicrobial Properties of Recombinant ASABF, an Antimicrobial Peptide Isolated from the NematodeAscaris suum

2000 ◽  
Vol 44 (10) ◽  
pp. 2701-2705 ◽  
Author(s):  
Hong Zhang ◽  
Shigenobu Yoshida ◽  
Tomoyasu Aizawa ◽  
Ritsuko Murakami ◽  
Masato Suzuki ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Minimum Bactericidal Concentration ◽  
Expression System ◽  
Antimicrobial Properties ◽  
Gram Negative Bacteria ◽  
Disulfide Bridges ◽  
Yeast Expression System ◽  
Gram Positive Bacteria ◽  
Low Ionic Strength

ABSTRACT ASABF is a CSαβ-type antimicrobial peptide that contains four intramolecular disulfide bridges (Y. Kato and S. Komatsu, J. Biol. Chem. 271:30493–30498, 1996). In the present study, a recombinant ASABF was produced by using a yeast expression system, and its antimicrobial activity was characterized in detail. The recombinant ASABF was active against all gram-positive bacteria tested (7 of 7; minimum bactericidal concentration [MBC], 0.03 to 1 μg/ml) exceptLeuconostoc mesenteroides, some gram-negative bacteria (8 of 14; MBC, >0.5 μg/ml), and some yeasts (3 of 9; MBC >3 μg/ml). Slight hemolytic activity (4.2% at 100 μg/ml) against human erythrocytes was observed only under low-ionic-strength conditions. Less than 1 min of contact was enough to kill Staphylococcus aureus ATCC 6538P. The bactericidal activity against S. aureus was inhibited by salts.

scholarly journals Inhibitory Spectra and Modes of Antimicrobial Action of Gallotannins from Mango Kernels (Mangifera indicaL.)

2011 ◽  
Vol 77 (7) ◽  
pp. 2215-2223 ◽  
Author(s):  
Christina Engels ◽  
Andreas Schieber ◽  
Michael G. Gänzle
Keyword(s):  
Staphylococcus Aureus ◽  
Wild Type Strain ◽  
Antimicrobial Activities ◽  
Resistance Mechanisms ◽  
Gram Negative Bacteria ◽  
Wild Type ◽  
Gram Positive Bacteria ◽  
Food Borne ◽  
Membrane Bound ◽  
Bacteria And Fungi

ABSTRACTThis study investigated the antimicrobial activities and modes of action of penta-, hexa-, hepta-, octa-, nona-, and deca-O-galloylglucose (gallotannins) isolated from mango kernels. The MICs and minimum bactericidal concentrations (MBCs) against food-borne bacteria and fungi were determined using a critical dilution assay. Gram-positive bacteria were generally more susceptible to gallotannins than were Gram-negative bacteria. The MICs of gallotannins againstBacillus subtilis,Bacillus cereus,Clostridium botulinum,Campylobacter jejuni,Listeria monocytogenes, andStaphylococcus aureuswere 0.2 g liter−1or less; enterotoxigenicEscherichia coliandSalmonella entericawere inhibited by 0.5 to 1 g liter−1, and lactic acid bacteria were resistant. The use of lipopolysaccharide mutants ofS. entericaindicated that the outer membrane confers resistance toward gallotannins. Supplementation of LB medium with iron eliminated the inhibitory activity of gallotannins againstStaphylococcus aureus, and siderophore-deficient mutants ofS. entericawere less resistant toward gallotannins than was the wild-type strain. Hepta-O-galloylglucose sensitizedLactobacillus plantarumTMW1.460 to hop extract, indicating inactivation of hop resistance mechanisms, e.g., the multidrug resistance (MDR) transporter HorA. Carbohydrate metabolism ofLactococcus lactisMG1363, a conditionally respiring organism, was influenced by hepta-O-galloylglucose when grown under aerobic conditions and in the presence of heme but not under anaerobic conditions, indicating that gallotannins influence the respiratory chain. In conclusion, the inhibitory activities of gallotannins are attributable to their strong affinity for iron and likely additionally relate to the inactivation of membrane-bound proteins.

scholarly journals A study of antimicrobial activities of aqueous and ethanolic extract of bee pollen against

2021 ◽  
Author(s):  
Kasim Roba Jilo
Keyword(s):  
Medicinal Plants ◽  
Aqueous Extract ◽  
Antimicrobial Properties ◽  
Ethanolic Extract ◽  
Antimicrobial Activities ◽  
Distilled Water ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bee Pollen ◽  
Stock Solutions

Abstract Background Ethiopia is one of the plant species-rich countries in the world and the center of origin of many medicinal plants. Studying antimicrobial activities of pollen is vivacious to investigate plant resources for medicinal values and the study was conducted to evaluate antimicrobial properties of bee pollen against mentioned bacteria. Methods Completely Randomized Design was used for laboratory work. After adjusting turbidity, consistent growth of bacterial culture was made using a sterilized cotton swab. 20 grams of bee pollen was added to 200 ml of distilled water as well as ethanol and finally, the extract was filtered by Whatman filter by paper, dried and weighted and stock solutions were made as follows,3.6 gm. was added to 12 ml of distilled water to prepare stock solutions as follows 3.6:12 = 0.3 x \({10}^{6}\) = 3 x \({10}^{5}\) ppm stock solution and antimicrobial activities of pollen were tested against mentioned bacteria. Data were imported to R software version 3.44. Multilevel analysis was used to see the interaction between bacteria species and each concentration of pollen and Anova was used to see the significance of these concentrations on bacteria species. A p-value of < 0.05 was considered statistically significant. Results Results indicated that bacteria were more inhibited at 72 hours than 48 and 24 hours and the results showed an ethanolic extract of bee pollen had antimicrobial activities against both Gram-negative and Gram-positive bacteria mentioned above. Time has significant effects on tested bacteria (p = 0.000) and treatments have significant effects on tested organisms (p = 0.000). The ethanolic extract inhibited the growth of more Gram-negative bacteria: Escherichia coli and Shigella boydii. Bacillus subtilis was mostly inhibited by aqueous extract of bee pollen than others. Conclusions Ethanolic extract of pollen had antibacterial activities against all tested bacterial strains even though it is concentration and time-based. The ethanolic extract inhibited more Gram-negative bacteria relatively while aqueous extract inhibited more Gram-positive relatively. Negative controls (sterilized water) didn’t show any antimicrobial properties, while positive control (Chloramphenicol) had antimicrobial activities. Further isolation and characterization of bioactive compounds from pollen are useful to develop a novel botanical formulation for further applications from the pollen of medicinal plants.

scholarly journals Synthesis of cyclotetrapeptide analogues of c-PLAI and evaluation of their antimicrobial properties

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Rani Maharani ◽  
Orin Inggriani Napitupulu ◽  
Jelang M. Dirgantara ◽  
Ace Tatang Hidayat ◽  
Dadan Sumiarsa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Properties ◽  
Trichophyton Mentagrophytes ◽  
Solution Phase ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Aromatic Residues ◽  
Gram Positive Bacteria ◽  
Lysine Residues ◽  
Bacteria And Fungi

Antimicrobial peptides (AMPs) are interesting compounds owing to their ability to kill several pathogens. In order to identify new AMPs, c-PLAI analogues were synthesized and evaluated together with their linear precursors for their antimicrobial properties against two Gram-positive bacteria ( Staphylococcus aureus and Bacillus cereus ), two Gram-negative bacteria ( Escherichia coli and Klebsiella pneumoniae ), and two fungal strains ( Candida albicans and Trichophyton mentagrophytes ). The new c-PLAI analogues were prepared through a combination of solid- and solution-phase syntheses, as previously employed for the synthesis of c-PLAI. The antimicrobial activity tests showed that the synthetic parent peptide c-PLAI was inactive or weakly active towards the bioindicators employed in the assay. The tests also indicated that cyclic c-PLAI analogues possessed enhanced antimicrobial properties against most of the bacteria and fungi tested. Furthermore, this study revealed that analogues containing cationic lysine residues displayed the highest activity towards most bioindicators. A combination of lysine and aromatic residues yielded analogues with broad-spectrum antimicrobial properties.

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