scholarly journals Synthesis and Antimicrobial Evaluation of Side-Chain Derivatives based on Eurotiumide A

Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 92
Author(s):  
Nakayama ◽  
Sato ◽  
Nakamura ◽  
Hamada ◽  
Nagano ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Iodine Atom ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antimicrobial Activities ◽  
Side Chain ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Antimicrobial Evaluation ◽  
Derivatives Of

Side-chain derivatives of eurotiumide A, a dihydroisochroman-type natural product, have been synthesized and their antimicrobial activities described. Sixteen derivatives were synthesized from a key intermediate of the total synthesis of eurotiumide A, and their antimicrobial activities against two Gram-positive bacteria, methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA), and a Gram-negative bacterium, Porphyromonas gingivalis, were evaluated. The results showed that derivatives having an iodine atom on their aromatic ring instead of the prenyl moiety displayed better antimicrobial activity than eurotiumide A against MSSA and P. gingivalis. Moreover, we discovered that a derivative with an isopentyl side chain, which is a hydrogenated product of eurotiumide A, is the strongest antimicrobial agent against all three strains, including MRSA.

scholarly journals Antimicrobial Evaluation of Leaf and Stem Extract of Cordia macleodii

2014 ◽  
Vol 1 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Deepkumar Joshi ◽  
Rinku Patel ◽  
Nupur Patel ◽  
Devendra Patel ◽  
Chintan Pandya
Keyword(s):  
Antimicrobial Activities ◽  
Maximum Amount ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Antifungal Potential ◽  
Stem Extract ◽  
Antimicrobial Evaluation ◽  
Antibacterial And Antifungal

The leaf and stem of cordia macleodii plant were investigated for evaluating antibacterial and antifungal properties.Different extracts of leaf and stem viz. double distilled water, methanol, ethyl acetate ane n-hexane were collectedand content was optimized for the maximum amount of extraction with varying time of 6 and 12 h. The extracts weretested for their antimicrobial activities against gram-positive bacteria (B. sutilis), gram-negative bacteria (E. coli) andfungi (A. niger). The extracts were found to be more active against bacteria as compared to fungi. It was also observedthat the antibacterial and antifungal potential of the water extracts were found to be excellent as 1A (38 mm) and 1B (22mm) compared to the other extracts. Graphical Abstract:

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.

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.

Silver Oxide–Copper Oxide Nanocomposite Preparation and Antimicrobial Activity as a Source for the Treatment of Fish Diseases

2017 ◽  
pp. 140-151
Author(s):  
Sayed Reza Shaffiey ◽  
Sayedeh Fatemeh Shaffiey
Keyword(s):  
Aeromonas Hydrophila ◽  
Bacterial Infections ◽  
Antimicrobial Activities ◽  
Cuo Nanoparticles ◽  
Negative Bacterium ◽  
Electron Micrograph ◽  
X Ray Diffraction ◽  
Gram Negative ◽  
Transmission Electron ◽  
Scanning Electron

Aeromonas hydrophila is a heterotrophic, gram negative bacterium which is primary or secondary cause of ulcers, fin rot, tail rot, and hemorrhagic septicaemia in fish. The treatments for this infection are only restricted to some antibiotics. So, novel materials are being searched for combating with bacterial infections and the resulting consequences. In this chapter, Ag2O/CuO nanocomposites were synthesized chemically and characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM) and transmission electron microscope (TEM). The antimicrobial activities of Ag2O/CuO nanoparticles (NPs), was checked by both well diffusion and turbidometric (spectrophotometric) method. Synthesized nanoparticles exhibited their antimicrobial efficacy in both the standard inhibitory assays; these results thus provide a scope for further research on the application of Ag2O/CuO nanoparticles as disinfectant and/or antibiotic in the fishery industry.

scholarly journals SYNTHESIS, CHARACTERIZATION, AND ANTIMICROBIAL EVALUATION OF NEW N-PHENYLCINNAMAMIDE DERIVATIVES LINKED TO ASPIRIN AND IBUPROFEN

2018 ◽  
Vol 11 (10) ◽  
pp. 443
Author(s):  
Ameer H Alwash ◽  
Alaa M Mahdi ◽  
Haider J Al-karagully
Keyword(s):  
Ethyl Chloroformate ◽  
Resonance Spectroscopy ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Antimicrobial Evaluation ◽  
Ester Linkage ◽  
Different Strains ◽  
Antibacterial And Antifungal ◽  
Antibacterial Evaluation

Objective: The objective of this study was to synthesize phenylcinnamamide (substituted acetanilide chalcone) derivatives linked to aspirin and ibuprofen with potential antibacterial and antifungal activity.Methods: Substituted acetanilide compounds were reacted with different arylaldehydes through Claisen-Schmidt condensation in the presence of KOH. They formed differently substituted acetanilide chalcones (1a-e) which are linked to aspirin and ibuprofen through an ester linkage to form compounds (2a-j) using ethyl chloroformate (ECF) as a catalyst.Results: The synthesized compounds have been characterized by elemental analysis, Fourier transform infrared and1H-nuclear magnetic resonance spectroscopy. An antibacterial evaluation was achieved for Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) and antifungal for Candida albicans.Conclusion: Compounds (2a-j) have shown intermediate antimicrobial activity against different strains of microorganisms.

Fusobacterium nucleatum, the first Gram-negative bacterium demonstrated to produce polyglutamate

2009 ◽  
Vol 55 (5) ◽  
pp. 627-632 ◽  
Author(s):  
Thomas Candela ◽  
Marie Moya ◽  
Michel Haustant ◽  
Agnès Fouet
Keyword(s):  
In Silico Analysis ◽  
Fusobacterium Nucleatum ◽  
Gram Negative Bacteria ◽  
Negative Bacterium ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
The Third ◽  
Gram Negative Organisms ◽  
First Time

Poly-γ-glutamate has been described in many Gram-positive organisms. When anchored to the surface, it is a capsule and as such a virulence factor. Based on sequence similarities, few Gram-negative organisms have been suggested to synthesize poly-γ-glutamate. For the first time, a Gram-negative bacterium, Fusobacterium nucleatum , is shown to produce and secrete poly-γ-glutamate. Putative poly-γ-glutamate-synthesizing genes from Gram-negative organisms have been compared with their Gram-positive homologs by in silico analysis, i.e., gene sequence and phylogenetic analysis. Clusters of three instead of four genes were highlighted by our screen. The products of the first two genes display similarity with their Gram-positive equivalents, yet the sequences from the Gram-negative organisms can be distinguished from those of the Gram-positives. Interestingly, the sequence of the predicted product of the third gene is conserved among Gram-negative bacteria but displays no similarity to that of either the third or fourth gene of the Gram-positive operons. It is suggested that, like for Gram-positive bacteria, poly-γ-glutamate has a role in virulence for pathogens and one in survival for other Gram-negative bacteria.

scholarly journals Synthesis and Evaluation of Antimicrobial and Cytotoxic Activity of Oxathiine-Fused Quinone-Thioglucoside Conjugates of Substituted 1,4-Naphthoquinones

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3577
Author(s):  
Yuri E. Sabutski ◽  
Ekaterina S. Menchinskaya ◽  
Ludmila S. Shevchenko ◽  
Ekaterina A. Chingizova ◽  
Artur R. Chingizov ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Cytotoxic Activity ◽  
Antimicrobial Activities ◽  
Biologically Active ◽  
Hydroxyl Group ◽  
Diffusion Method ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
High Cytotoxic Activity ◽  
Derivatives Of

A series of new tetracyclic oxathiine-fused quinone-thioglycoside conjugates based on biologically active 1,4-naphthoquinones and 1-mercapto derivatives of per-O-acetyl d-glucose, d-galactose, d-xylose, and l-arabinose have been synthesized, characterized, and evaluated for their cytotoxic and antimicrobial activities. Six tetracyclic conjugates bearing a hydroxyl group in naphthoquinone core showed high cytotoxic activity with EC50 values in the range of 0.3 to 0.9 μM for various types of cancer and normal cells and no hemolytic activity up to 25 μM. The antimicrobial activity of conjugates was screened against Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus), Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), and fungus Candida albicans by the agar diffusion method. The most effective juglone conjugates with d-xylose or l-arabinose moiety and hydroxyl group at C-7 position of naphthoquinone core at concentration 10 µg/well showed antimicrobial activity comparable with antibiotics vancomicin and gentamicin against Gram-positive bacteria strains. In liquid media, juglone-arabinosidic tetracycles showed highest activity with MIC 6.25 µM. Thus, a positive effect of heterocyclization with mercaptosugars on cytotoxic and antimicrobial activity for group of 1,4-naphthoquinones was shown.

scholarly journals Synthesis, Characterization and Antibacterial Activity of 2-Phenylsulphonamide Derivatives of Some Amino Acids

2016 ◽  
Vol 70 ◽  
pp. 42-47
Author(s):  
Chinyere Benardette Chinaka Ikpa ◽  
Uchechukwu C. Okoro ◽  
Collins I. Ubochi ◽  
Kieran O. Nwanorh
Keyword(s):  
Amino Acids ◽  
Inhibitory Concentration ◽  
Gram Negative Bacteria ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Simple Substitution ◽  
Ft Ir ◽  
Derivatives Of

The 2-phenylsulphonamide derivatives of amino acids were synthesis by simple substitution of benzenesulphonylchloride (6) with amino acids (1-5) containing pharmacological active functionalities. Structures of the synthesised compounds (7a-7e) were characterised using FT-IR, NMR(1H,13C) and elemental analysis. The anti bacterial activities of the synthesised compounds were evaluated against gram positive bacteria: Staph and Streptococcus, gram negative bacteria: E-coli, Klebsiella, Proteus, and pseudomonas using 200 µl of 10 mg/ml and minimum inhibitory concentration (MIC) were also determined. The compounds exhibited effective anti bacterial properties though some are not more active than the standard drug ciprofloxacin.

scholarly journals Chemical Composition and Antimicrobial Activity of Two Sri Lankan Lichens, Parmotrema rampoddense, and Parmotrema tinctorum against Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Polwatta Samaraweera Arachchige Ishara Shiromi ◽  
Ruwani Punyakanthi Hewawasam ◽  
Rankoth Gedara Udeni Jayalal ◽  
Hasanga Rathnayake ◽  
Weerasinghe Mudiyanselage Dilip Gaya Bandara Wijayaratne ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Chemical Composition ◽  
Secondary Metabolites ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Ethanol Extract ◽  
Aqueous Extracts ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Parmotrema Tinctorum

Introduction. Medicinal utility of lichens is ascribed to the presence of various secondary metabolites of low molecular weight and they have been used in traditional medicine including Ayurveda in the treatment of wounds and skin disorders. Despite the urgent need to effectively address the antibiotic resistance worldwide, the discovery of new antibacterial drugs has declined in the recent past. This emphasizes the increasing importance of investigating and developing new classes of antibiotics that can withstand antibiotic resistance. Aims of the study. The present study was conducted to investigate the chemical composition and the antibacterial activity of hexane, ethanol, and aqueous extracts of Parmotrema rampoddense and Parmotrema tinctorum, two lichens collected from Belihuloya, Sri Lanka, against Gram-negative and Gram-positive bacteria including twenty clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). Materials and methods. Phytochemical analysis, thin layer chromatography (TLC), and Gas Chromatography Mass Spectrometry (GC-MS) were performed to determine the chemical composition of the two lichens. Hexane, ethanol, and aqueous extracts of both lichens were tested against clinical isolate of Gram-negative and Gram-positive bacteria including twenty clinical isolates of MRSA. Bacterial susceptibility was tested using a disc diffusion assay. Minimum inhibitory concentration (MIC) was determined by a broth microdilution method. Vancomycin was used as the positive control. Results. Alectorialic acid, atranorin, atraric acid, orcinol, and O-orsellinaldehyde were among the secondary metabolites identified by the TLC and GC-MS analysis. None of the lichen extracts were active against Gram-negative bacteria but both lichens showed a concentration-dependent activity against methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA. Ethanol extract of P. rampoddense showed the highest activity against MSSA with the MIC, 0.0192 mg/ml, but all MRSA isolates investigated showed MIC between 0.096 and 2.4 mg/ml for the same extract. Conclusion. Both lichens, P. rampoddense and P. tinctorum, represent potentially important sources of future antimicrobial drugs. Further investigation on the ethanol extract of P. rampoddense will enable us to determine the most active phytoconstituents responsible for the activity, their mechanism of action against bacterial pathogens, and also their cytotoxicity against normal cells.

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