scholarly journals Synthesis and Antimicrobial Activity of Burkholderia-Related 4-Hydroxy-3-Methyl-2-Alkenylquinolones (HMAQs) and Their N-Oxide Counterparts

2020 ◽  
Author(s):  
Marianne Piochon ◽  
Pauline M. L. Coulon ◽  
Armand Caulet ◽  
Marie-Christine Groleau ◽  
Eric Déziel ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biologically Active ◽  
Specific Class ◽  
Gram Positive ◽  
Carbonate Group ◽  
Gram Positive Bacteria ◽  
Alkenyl Chain ◽  
Optimized Conditions ◽  
Burkholderia Ambifaria

ABSTRACT: The Burkholderia genus offers a promising potential in medicine because of the diversity of biologically active natural products encoded in its genome. Some pathogenic Burkholderia spp. biosynthesize a specific class of antimicrobial 2-alkyl-4(1H)-quinolones, i.e., 4-hydroxy-3-methyl-2-alkenylquinolones (HMAQs) and their N-oxide derivatives (HMAQNOs). Herein, we report the synthesis of a series of six HMAQs and HMAQNOs featuring a trans-∆<sup>2</sup> double bond at the C2-alkyl chain. The quinolone scaffold was obtained via the Conrad-Limpach approach while the (E)-2-alkenyl chain was inserted through Suzuki-Miyaura cross-coupling under microwave radiation without noticeable isomerization according to the optimized conditions. Subsequent oxidation of enolate-protected HMAQs cleanly led to the formation of HMAQNOs following cleavage of the ethyl carbonate group. Synthetic HMAQs and HMAQNOs were in vitro evaluated for their antimicrobial activity against different Gram-negative and Gram-positive bacteria as well as against fungi and yeasts. The biological results support and extend the potential of HMAQs and HMAQNOs as antimicrobials, especially against Gram-positive bacteria. We also confirm the involvement of HMAQs in the autoregulation of the Hmq system in Burkholderia ambifaria.

scholarly journals Synthesis and Antimicrobial Activity of Burkholderia-Related 4-Hydroxy-3-Methyl-2-Alkenylquinolones (HMAQs) and Their N-Oxide Counterparts

2020 ◽  
Author(s):  
Marianne Piochon ◽  
Pauline M. L. Coulon ◽  
Armand Caulet ◽  
Marie-Christine Groleau ◽  
Eric Déziel ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biologically Active ◽  
Specific Class ◽  
Gram Positive ◽  
Carbonate Group ◽  
Gram Positive Bacteria ◽  
Alkenyl Chain ◽  
Optimized Conditions ◽  
Burkholderia Ambifaria

ABSTRACT: The Burkholderia genus offers a promising potential in medicine because of the diversity of biologically active natural products encoded in its genome. Some pathogenic Burkholderia spp. biosynthesize a specific class of antimicrobial 2-alkyl-4(1H)-quinolones, i.e., 4-hydroxy-3-methyl-2-alkenylquinolones (HMAQs) and their N-oxide derivatives (HMAQNOs). Herein, we report the synthesis of a series of six HMAQs and HMAQNOs featuring a trans-∆<sup>2</sup> double bond at the C2-alkyl chain. The quinolone scaffold was obtained via the Conrad-Limpach approach while the (E)-2-alkenyl chain was inserted through Suzuki-Miyaura cross-coupling under microwave radiation without noticeable isomerization according to the optimized conditions. Subsequent oxidation of enolate-protected HMAQs cleanly led to the formation of HMAQNOs following cleavage of the ethyl carbonate group. Synthetic HMAQs and HMAQNOs were in vitro evaluated for their antimicrobial activity against different Gram-negative and Gram-positive bacteria as well as against fungi and yeasts. The biological results support and extend the potential of HMAQs and HMAQNOs as antimicrobials, especially against Gram-positive bacteria. We also confirm the involvement of HMAQs in the autoregulation of the Hmq system in Burkholderia ambifaria.

scholarly journals The Search for Biologically Active Compounds in the Series of N-ethoxyethylpiperidine Derivatives

2019 ◽  
Vol 21 (2) ◽  
pp. 125
Author(s):  
U.B. Issayeva ◽  
G.S. Akhmetova ◽  
U.M. Datkhayev ◽  
M.T. Omyrzakov ◽  
K.D. Praliyev ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biologically Active ◽  
Hydroxyl Group ◽  
Diffusion Method ◽  
Acylation Reaction ◽  
Gram Positive Bacteria ◽  
Cyclopropanecarboxylic Acid ◽  
Yeast Fungus ◽  
Acid Esters

With the aim to introduce fragment of cyclopropane and fragments of p-, m-, o-fluorophenyls into the structures of N-ethoxyethylpiperidines, acylation of oxime and phenylacetylenic alcohol of 1-(2-ethoxyethyl)-4-ketopiperidine by cyclopropanecarbonylchloride was carried out; on the basis of 1-(2-ethoxyethyl)-4-ethynyl-4-hydroxypiperidine (cascaine alcohol), acylation by 4-fluoro-, 3-fluoro-, 2-fluorobenzoylchlorides was carried out with formation of the corresponding piperidine containing hydrochlorides of cyclopropanecarboxylic acid esters and para-, meta-, ortho-fluorobenzoic esters. Acylation reaction on the hydroxyl group of compounds is carried out in absolute dioxane, the acylating agents are cyclopropanecarbonylchloride, p-, m-, o-fluorobenzoyl chlorides taken in excess. The obtained esters of cyclopropanecarboxylic and para-, meta-, ortho-fluorobenzoic acids are crystalline substances with a clear melting point, well soluble in water, ethanol, acetone. P-fluorobenzoates are obtained with better yields, m-fluorobenzoates occupy an intermediate position, and o-fluorobenzoates are formed with the lowest yields. The best yields of fluorobenzoates are obtained using dioxane as a solvent. Para-, meta-, ortho-fluorobenzoic esters of 1-(2-ethoxyethyl)-4-ethynyl-4-hydroxypiperidine coded A-4 – A-6 were studied for the presence of antimicrobial activity, the actions of these preparations were evaluated in vitro in relation to strains of gram-positive bacteria Staphylococcus aureus, Bacillus subtilis, gram-negative strains of Escheriсhia coli, Pseudomonas aeruginosa and to yeast fungus Сandida albicans by the diffusion method into agar (holes). Introduction of fluorine atom into the structure of cascaine lead to manifestation of antimicrobial activity.

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.

Biologically active binaphthol-scaffolded imidazolium salts

MedChemComm ◽  
2014 ◽  
Vol 5 (4) ◽  
pp. 436-440 ◽  
Author(s):  
Marc Vidal ◽  
Claude-Rosny Elie ◽  
Shirley Campbell ◽  
Audrey Claing ◽  
Andreea R. Schmitzer
Keyword(s):  
Antimicrobial Activity ◽  
Lipid Membrane ◽  
Biologically Active ◽  
Imidazolium Salts ◽  
Gram Positive ◽  
Gram Positive Bacteria

This work describes the antimicrobial activity and selectivity for Gram-positive bacteria of imidazolium-functionalized binols, as a result of their insertion into the lipid membrane and alteration of its permeability.

scholarly journals Chemical Composition and in vitro Antimicrobial Activity of the Essential Oil of the Flowers of Tridax procumbens

2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Rajesh K. Joshi ◽  
Vijaylaxmi Badakar
Keyword(s):  
Gas Chromatography ◽  
Antimicrobial Activity ◽  
Essential Oil ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Flame Ionization ◽  
Tridax Procumbens

The essential oil of the flowers of Tridax procumbens L. was obtained by hydro-distillation and analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Twenty-six compounds were identified, which comprised 90.6% of the total constituents. The most abundant compound was ( Z)-falcarinol (25.9%), followed by α-selinene (15.3%), limonene (8.3%) and zerumbone (4.3%). Antimicrobial activity was tested against six Gram-positive and eight Gram-negative bacteria, and three fungi. The oil was active against the tested Gram-positive bacteria at a concentration range of 0.14 ± 0.03 - 0.57±0.05 mg/mL, while 0.67 ± 0.12 - 4.58 ± 0.41 mg/mL was effective against the studied Gram-negative bacteria. Remarkable antifungal activity was found against the tested fungi at a concentration range of 0.06 ± 0.008 - 0.10 ± 0.01 mg/mL.

scholarly journals Antimicrobial activity of crude henna extract against Gram-positive bacteria

2021 ◽  
Vol 5 (3) ◽  
Keyword(s):  
Antimicrobial Activity ◽  
Crude Extract ◽  
Antibacterial Properties ◽  
Diffusion Method ◽  
Drug Resistant ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Bacterial Agent ◽  
Henna Extract

Objectives: This study aimed to examine the effect of ethanolic extract of local Basra henna leaves on Gram-positive bacteria species. Also, to assess the antibacterial properties of henna crude extract in vitro and compare them with antibiotics. Methods: In this study, Lawsonia inermis (henna) leaves were extracted with ethanol using the solvent extraction technique. The pathogens were isolated from wound samples obtained from hospitalized patients in two different hospitals in Duhok city. The culture of thirty isolates had been recognized by routine methods. Different concentrations of ethanol crude extract were acquired and bio-assayed in vitro to inhibit the growth of five human pathogenic Gram-positive bacteria. Agar well diffusion assay was used for achieving henna antibiotic activity. Moreover, an antibiotics susceptibility test was done by the disk diffusion method using the Muller-Hinton agar medium. Results: The growth of all tested bacteria was suppressed to various degrees by increasing the concentration of the extract. The data has revealed that Staphylococcus aureus was more sensitive than other examined isolates, where the diameter zone of inhibition was ranging from 16-27, 14-25, and 8-18 mm for Staphylococcus epidermidis, Lactobacillus spp. and Streptococcus pneumonia respectively. The antimicrobial activity of henna extract indicates that it is suitable for being used as significant certain medications. Consequently, henna is active to serve as an anti-bacterial agent against multi-drug resistant Gram-positive bacteria. Conclusion: The antimicrobial activity of henna extract indicates that it is suitable for being used as significant certain medications. Consequently, henna is active to serve as an anti-bacterial agent against multi-drug resistant Gram-positive bacteria.

scholarly journals IN VITRO ANTIMICROBIAL ACTIVITY OF CARVACROL AGAINST SHRIMP PATHOGENS AND ITS USE AS FEED ADDITIVE FOR THE PACIFIC WHITE SHRIMP

2021 ◽  
Vol 47 ◽  
pp. e645
Author(s):  
Jaqueline da Rosa COELHO ◽  
Karolina Victória ROSA ◽  
Jamilly Sousa ROCHA ◽  
Norha Constanza Bolívar RAMÍREZ ◽  
Marcelo MARASCHIN ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Vibrio Harveyi ◽  
Pacific White Shrimp ◽  
The Other ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Vitro Effect

This study aimed to evaluate the in vitro effect of carvacrol on different microorganisms of importance in shrimp farming, as well as its in vivo effect on zootechnical, immunological and microbiological performance, as well as resistance, of Litopenaeus vannamei challenged with Vibrio parahaemolyticus. In particular, the antimicrobial activity of carvacrol was evaluated in vitro by analysis of the minimum inhibitory concentration (MIC) and by agar diffusion disc with Gram-negative and Gram-positive bacteria. The in vivo experiment was conducted using different concentrations of carvacrol (1, 3, 4 and 6 mg mL-1) added to shrimp feed, together with a control diet without carvacrol. After four weeks, zootechnical, immunological and microbiological parameters, as well as resistance, of animals challenged with V. parahaemolyticus were evaluated. The MIC of Vibrio alginolyticus and Vibrio harveyi was 0.078 mg mL-1, while for the other bacteria, it was 0.156 mg mL-1 of carvacrol. The greatest halos of inhibition were observed in V. parahaemolyticus and Vibrio harveyi with significant differences demonstrated for the other microorganisms, except Escherichia coli. The in vivo results showed no significant differences among treatments. In conclusion, the antimicrobial activity of carvacrol was confirmed with Gram-negative and Gram-positive bacteria, and it is suggested that its antimicrobial potential is more effective against Vibrio spp. However, the concentrations of carvacrol used in vivo did not affect the parameters evaluated.

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