scholarly journals Synthesis and Evaluation of Novel Fluorinated 2-Styrylchromones as Antibacterial Agents

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Mehbub Momin ◽  
Deresh Ramjugernath ◽  
Hafizah Chenia ◽  
Neil A. Koorbanally
Keyword(s):  
Antibacterial Activity ◽  
Phenyl Ring ◽  
Antibacterial Agents ◽  
Klebsiella Pneumonia ◽  
Gram Negative Bacteria ◽  
Fluorine Substitution ◽  
Single Strain ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Activity Indices

A range of fluorinated 2-styrylchromones (5a–g) of which six were new (5a–f) were prepared in three steps using the Baker-Venkataraman rearrangement along with two methoxylated derivatives (5h-i) and a methylenedioxy derivative (5j) and screened for their antibacterial activity using Gram-positive bacteria (Staphylococcus aureus, sciuri, andxylosusas well asBacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, andKlebsiella pneumonia). The compounds were most effective againstB. subtilisfollowed byS. aureusand a single strain ofE. coli(ATCC 25922). Difluorination on the phenyl ring was shown to enhance antibacterial activity, and fluorine substitution at the 6 position was shown to be far superior to substitution at the 7 position. In comparison to tetracycline, the activity indices of the fluorinated styrylchromones ranged from 0.50 to 0.75 againstB. subtilis. The crystal structure of 2′-fluoro-2-styrylchromone is also presented, and the molecule was shown to be planar.

scholarly journals Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles for antibacterial photodynamic therapy

2019 ◽  
Vol 18 (5) ◽  
pp. 1147-1155 ◽  
Author(s):  
Rehan Khan ◽  
Melis Özkan ◽  
Aisan Khaligh ◽  
Dönüs Tuncel
Keyword(s):  
Antibacterial Activity ◽  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Water Dispersible ◽  
Gram Positive Bacteria ◽  
High Yields

Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles have the ability to generate singlet oxygen in high yields and exhibit light-triggered antibacterial activity against Gram negative bacteria, E. coli as well as Gram positive bacteria, B. subtilis.

Synthesis, Characterization, and Antibacterial Evaluation of Curcumin-Sulfanilamide Compound

2020 ◽  
Vol 840 ◽  
pp. 265-269
Author(s):  
Nurjanah Nurjanah ◽  
Endang Saepudin
Keyword(s):  
Antibacterial Activity ◽  
Functional Group ◽  
Biological Activities ◽  
Curcuma Longa ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Ftir Spectrophotometry

Curcumin, a diarylheptanoids compound which isolated primary from Curcuma longa, exhibits a variety of exciting biological activities, including as an antibacterial agent. In the present study, a sulfanilamide-contained curcumin compound was synthesized and characterized to investigate the antibacterial activity against gram-positive bacteria S. aureus, B. subtilis and gram-negative bacteria E. coli. The characterization of the synthesized compound was determined by analysing peak absorbance, functional group, and molecular weight using mass spectroscopy, UV/Vis and FTIR spectrophotometry. Curcumin-sulfanilamide compound exhibited the best antibacterial activity against gram-negative bacteria compared to curcumin and the curcumin-derived compound containing isoxazole with inhibitory zone of 11 mm.

scholarly journals Synthesis and Antibacterial Activity of Chalcones and Pyrimidine-2-ones

2005 ◽  
Vol 2 (2) ◽  
pp. 109-112
Author(s):  
A. K. Parekh ◽  
K. K. Desai
Keyword(s):  
Antibacterial Activity ◽  
Spectral Data ◽  
Elemental Analysis ◽  
Aromatic Aldehydes ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
H Nmr

Some new chalcones have been prepared by Claisen-schmidt condensation of ketone and different aromatic aldehydes. These chalcones on condensation with urea in presence of acid gave Pyrimidine-2-ones. The synthesized compounds have been characterized by elemental analysis, IR and1H NMR spectral data. They have been screened for their antibacterial activity against Gram positive bacteria B. subtillis & S. aureus and Gram negative bacteria E. coli & S. typhi.

scholarly journals 5-Bromo-1-(4-chlorobenzyl)-1H-indole-2-carboxamides as new potent antibacterial agents

2018 ◽  
Vol 24 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Yogesh D. Mane ◽  
Smita S. Patil ◽  
Dhanraj O. Biradar ◽  
Bhimrao C. Khade
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Internal Standards ◽  
Gram Negative ◽  
E Coli ◽  
High Antibacterial Activity

Abstract Ten 5-bromoindole-2-carboxamides were synthesized, characterized and evaluated for antibacterial activity against pathogenic Gram-negative bacteria Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella Typhi using gentamicin and ciprofloxacin as internal standards. Compounds 7a–c, 7g and 7h exhibit high antibacterial activity with a minimum inhibitory concentration (MIC) of 0.35–1.25 μg/mL. Compounds 7a–c exhibit antibacterial activities that are higher than those of the standards against E. coli and P. aeruginosa.

scholarly journals Antibacterial Activity of Hen Egg White Lysozyme Denatured by Thermal and Chemical Treatments

2018 ◽  
Vol 86 (4) ◽  
pp. 48 ◽  
Author(s):  
Rubén Vilcacundo ◽  
Pilar Méndez ◽  
Walter Reyes ◽  
Herman Romero ◽  
Adelita Pinto ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Lytic Activity ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Chemical Treatments ◽  
Egg White Lysozyme ◽  
Hen Egg White ◽  
Antibacterial Spectrum

The aim of this study was to increase the antibacterial spectrum of modified hen egg white lysozyme (HEWL) with thermal and chemical treatments against Gram-negative bacteria. The antibacterial activity of heat-denatured HEWL and chemical denatured HEWL against Gram-negative and Gram-positive bacteria was evaluated in 15 h of incubation tests. HEWL was denatured by heating at pH 6.0 and pH 7.0 and chemical denaturing was carried out for 1.0, 1.5, 2.0, and 4.0 h with DL-Dithiothreitol (DTT). HEWL modified by thermal and chemical treatments was characterized using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis method. Heat-denatured HEWL lytic activity against Micrococcus lysodeikticus lessened with increasing temperature and time of incubation with the chemical agent (DTT). The loss of lytic activity in modified HEWL suggests that the mechanism of action of the antibacterial activity is not dependent on the lytic activity. Thermal and chemical treatments of HEWL enabled the production of oligoforms and increased antibacterial activity over a wider spectrum. Heat-denatured HEWL at pH 6.0 and chemically-denatured HEWL increased the HEWL antibacterial spectrum against Gram-negative bacteria (Escherichia coli ATCC 25922). HEWL at 120 °C and pH 6.0 (1.0 mg/mL) inhibited 78.20% of the growth of E. coli. HEWL/DTT treatment for 4.0 h (1.0 mg/mL) inhibited 68.75% of the growth E. coli. Heat-denatured HEWL at pH 6.0 and pH 7.0 and chemically-denatured HEWL (1.0, 1.5, 2.0, and 4.0 h with DTT) were active against Gram-positive bacteria (Staphylococcus carnosus CECT 4491T). Heat-denatured and chemical-denatured HEWL caused the death of the bacteria with the destruction of the cell wall. LIVE/DEAD assays of fluorescent dye stain of the membrane cell showed membrane perturbation of bacteria after incubation with modified HEWL. The cell wall destruction was viewed using electron microscopy. The results obtained in this study suggest that heat-denatured HEWL at pH 6.0 and chemical-denatured HEWL treatments increase the HEWL antibacterial activity against Gram-negative bacteria.

scholarly journals Synthesis and Biological Screening of 3-Aryl-5-[(4′-Difluoromethoxy)(3′-Hydroxy)Phenyl]-4,5-Dihydro Isoxazole

2015 ◽  
Vol 47 ◽  
pp. 133-138
Author(s):  
V.N. Bhadani ◽  
H.D. Purohit ◽  
Dipak M. Purohit
Keyword(s):  
Antibacterial Activity ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Biological Activities ◽  
Gram Negative Bacteria ◽  
Biological Screening ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Therapeutic Activities

Isoxazoline derivatives shows various types of therapeutic activities like antimicrobial[1], anti-inflammatory[2], anticonvulsant[3], Hypoglycemic[4] etc. getting to synthesized in view of 3-Aryl-5-[(4′-difluoromethoxy)(3′-hydroxy)phenyl]-4,5-dihydro isoxazole (4a-4i) have been synthesized. All the newly synthesized compounds were screened for their antibacterial activity against S. aureus, M. luteus (Gram-positive bacteria), E. coli, S. thyphi (Gram-negative bacteria) and antifungal activity against Candida albicans (Fungi). The biological activities (MIC) of the synthesized compounds were compared with known standard drugs.

scholarly journals Synthesis, characterization and antibacterial evaluation of some sulfonamide Schiff base derivatives

2019 ◽  
Vol 10 (4) ◽  
pp. 3535-3543
Author(s):  
Mustafa M. AL-Hakiem ◽  
Rita S. Elias ◽  
Munther A. Mohammed-Ali
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Uv Light ◽  
Klebsiella Pneumonia ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Chemical Structures ◽  
Antibacterial Evaluation

New series of Schiff base compounds obtained from sulfa drugs have been synthesized by the reaction of sulfonamide compounds (sulfadiazine, sulfapyridine, sulfamethazine, or sulfamerazine) with corresponding aromatic aldehydes (3-pyridinecarboxaldehyde or 4-pyridinecarboxaldehyde). The synthesized compounds were characterized by FT-IR, ESI-Mass, and 1H-NMR spectroscopy to confirm the chemical structures of synthesized compounds. The purity of all synthesized compounds were verified using pre-coated TLC (MERCK) plates using dichloromethane: methanol (9:1) solvent system. The chromatographic plates were viewed under ultraviolet(UV) light at 254 nm The sulfonamide Schiff base compounds were tested for antibacterial evaluation against two pathogenic Gram-positive bacteria (Staphylococcus aureus, Streptococcus spp.) and two pathogenic Gram-negative bacteria (Escherichia coli and Klebsiella pneumonia). The antibacterial activity of synthesized compounds was evaluated by assessing the inhibitory concentration by measuring their inhibition zone versus certain kinds of standard antibiotics with concentrations (500, 750, and 1000) μg /ml. Most synthesized compounds at high concentration were moderately active against all tested bacteria ,compound SH7 showed best antibacterial activity for both (Gram-positive and Gram-negative) bacteria while SH8 compound exhibited moderate antibacterial activity against Gram-positive bacteria and weak activity (<10 mm) against Gram-negative bacteria and all synthesized compounds were less antibacterial activity for all tested bacterial strains than standard drugs.

scholarly journals Phytochemical screening and antibacterial activity of crude aqueous and ethanol extracts of Salvadora persica L. stem (Miswak) from Saudi Arabia

2015 ◽  
Vol 4 (5) ◽  
pp. 243-247
Author(s):  
Emad Mohamed Abdallah ◽  
◽  
Khalid Assaf Al Harbi ◽  
Keyword(s):  
Antibacterial Activity ◽  
Staphylococcus Epidermidis ◽  
Antimicrobial Effect ◽  
Penicillin G ◽  
Klebsiella Pneumonia ◽  
Gram Negative Bacteria ◽  
Salvadora Persica ◽  
Gram Positive Bacteria ◽  
Long Time ◽  
Ethanol Extracts

Since long time ago, medicinal plant products have been a rich source of antibacterial drugs. Salvadora persica L. stem is used basically for cleanse, get rid of microbes and the stink smell of the mouth. Phytochemical investigations on the aqueous and ethanol extracts of Salvadora persica L. stem revealed presence of some bioactive principles, such as Saponins, alkaloids, cardiac glycosides, Terpenoids and flavonoids. Antimicrobial investigation revealed presence of some degree of antimicrobial effect against some gram negative bacteria (Salmonella enterica ATCC 5174, Proteus vulgaris ATCC 49132, Klebsiella pneumonia ATCC 27736, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) and some gram positive bacteria (Bacillus cereus ATCC 10876, Staphylococcus epidermidis ATCC 49461, Staphylococcus aureus ATCC 25923). This antibacterial activity considered Competitor to penicillin G, but modest when compared to gentamicin. The antibiotic penicillin is collapsing and it is no longer a good option.

scholarly journals Explore the Potential of a Plant Phospholipase as an Antimicrobial

2020 ◽  
Author(s):  
Curtis Chen ◽  
Shanhui Xu ◽  
Yanran Li
Keyword(s):  
Antibacterial Agents ◽  
Gram Negative Bacteria ◽  
Global Public Health ◽  
Lower Efficiency ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Plant Lipase ◽  
Plant Enzymes ◽  
Shed Light

AbstractGlobal public health is increasingly threatened by the fast emergence of antibiotic resistance, and novel types of antibiotics are urgently needed. Metazoans have evolved their own antimicrobial mechanism, such as human group IIA secreted phospholipase A (sPLA2), which can efficiently inhibit the growth of gram-positive bacteria, but with much lower efficiency toward gram-negative bacteria. Here, we verified the antibacterial activity of a plant lipase, PLIP1 from Arabidopsis thaliana, against the gram-negative bacteria Escherichia coli, which belongs to the WHO priority 1 (critical) pathogen Enterobacteriaceae family. We also explored the potential of evolving PLIP1 as a more potent antimicrobial agent towards E. coli. Our results imply the possibility of using plant lipases as a potential antimicrobial and shed light on the future exploration of plant enzymes for novel and more efficient antibacterial agents.

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