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

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.

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3577
Author(s):  
Yuri E. Sabutski ◽  
Ekaterina S. Menchinskaya ◽  
Ludmila S. Shevchenko ◽  
Ekaterina A. Chingizova ◽  
Artur R. Chingizov ◽  
...  

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.


2020 ◽  
Author(s):  
Marianne Piochon ◽  
Pauline M. L. Coulon ◽  
Armand Caulet ◽  
Marie-Christine Groleau ◽  
Eric Déziel ◽  
...  

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.


Author(s):  
Marianne Piochon ◽  
Pauline M. L. Coulon ◽  
Armand Caulet ◽  
Marie-Christine Groleau ◽  
Eric Déziel ◽  
...  

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.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ayman El-Faham ◽  
Wael N. Hozzein ◽  
Mohammad A. M. Wadaan ◽  
Sherine N. Khattab ◽  
Hazem A. Ghabbour ◽  
...  

Three series of isatin derivatives [3-hydrazino, 3-thiosemicarbazino, and 3-imino carboxylic acid derivatives] were synthesized employing microwave irradiation. The prepared compounds were characterized by FT-IR, NMR, elemental analysis, and X-ray crystallography for derivatives5b. The synthesized compounds were screened for antimicrobial activity against selected bacteria and fungi. The results revealed that theN-alkyl isatin derivatives were biologically active with different spectrums activity. Most of the 3-hydrazino and 3-thiosemicarbazino isatin derivatives were biologically inactive and generally the active derivatives showed weak to moderate activity mainly against Gram-positive bacteria. The imino isatin carboxylic acid derivatives (2-[4-(1-benzyl-5-bromo-2-oxoindolin-3-ylideneamino) phenyl]acetic acid,5d) showed promising activity against all tested Gram-positive bacteria and against fungal pathogens.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mashooq Ahmad Bhat ◽  
Mohamed A. Al-Omar ◽  
Ahmed M. Naglah ◽  
Abdul Arif Khan

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.


2005 ◽  
Vol 60 (5-6) ◽  
pp. 385-388 ◽  
Author(s):  
Rubén García ◽  
Cesia Cayunao ◽  
Ronny Bocic ◽  
Nadine Backhouse ◽  
Carla Delporte ◽  
...  

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.


2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Eti Nurwening Sholikhah ◽  
Maulina Diah ◽  
Mustofa ◽  
Masriani ◽  
Susi Iravati ◽  
...  

Pycnarrhena cauliflora (Miers.) Diels., local name sengkubak, is one of indigenous plants from West Kalimantan that has been used as natural flavor. Pycnorrhena cauliflora is one of species of Menispermaceae family which is rich in bisbenzylisoquinoline alkaloids. This alkaloids are known to have various biological activities including antiprotozoal, antiplasmodial, antifungal and antibacterial activities. This study aimed to investigate antimicrobial activity of  the P. cauliflora (Miers.) Diels. methanolic extracts against gram-positive and gram-negative bacteria. The methanolic extract of P. cauliflora (Miers.) Diels., root, leaf and stem were prepared by maceration. The disk-diffusion method was then used to determine the antimicrobial activity of the extracts against Streptococcus pyogenes, S. mutants, Staphylococcus aureus, S. epidermidis, Salmonella typhi, Shigella flexneri, Pseudomonas aeruginosa and Escherichia coli after 18-24 h incubation at 37 oC. Amoxicillin was used as positive control for gram-positive bacteria and ciprofloxacin was used as gram-negative bacteria. The inhibition zones were then measured in mm. Analysis were conducted in duplicates. The results showed in general the methanolic extracts of P. cauliflora (Miers.) Diels. root (inhibition zone diameter= 10-23 mm) were more active than that leaf (0-15 mm) and stem (0-17 mm) extracts against gram-positive bacteria. The zone inhibition diameter of amoxicillin as positive control was 8-42 mm. In addition, the methanolic extracts of P. cauliflora (Miers.) Diels. root (12-17 mm) were also more active than that leaf (0-12 mm) and stem (0-12 mm) extracts against gram-negative bacteria. The zone inhibition diameter of ciprofloxacin as positive control was 33-36 mm. In conclusion, the methanolic extract of P. caulifloria (Miers.) Diels. root is the most extract active against both gram-positive and gram-negative bacteria. Further study will be focused to isolate active compounds in the methanolic extract of the root.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 465-466
Author(s):  
Cinta Sol ◽  
Mónica Puyalto ◽  
Bernat Canal ◽  
Ana Maria Carvajal ◽  
Manuel Gómez ◽  
...  

Abstract The aim of this study was to investigate the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of organic acid salts against six field isolates of Streptococcus suis. The three products evaluated were sodium salt of coconut fatty acids distillate (DIC) alone and two combinations with sodium butyrate (NaBut): DIC70:30, being 70% of NaBut protected with 30% of DIC; and DIC50:50, being 50% of NaBut protected with 50% of DIC. Antimicrobial susceptibility testing was performed to estimate the MIC values for each product and strain by the broth microdilution method at pH 6.0. MBC values were also determined by sub-culturing supernatant from wells without evident bacterial growth. The values of MIC50/MBC50 were calculated as the concentration which inhibited/killed 50% of the isolates tested. The MIC50 showed DIC as the most effective (8 ppm) against S. suis followed by DIC50:50 (32 ppm) and DIC70:30 (64 ppm). The MBC50 demonstrated a similar trend, DIC being the most effective (16 ppm) followed by DIC50:50 (64 ppm) and DIC70:30 (64 ppm). It is well known that butyric acid is a short-chain fatty acid which has strong antimicrobial activity against Gram-negative bacteria. In contrast, coconut fatty acids distillate is a medium-chain fatty acid source (MCFA) rich in lauric acid which has strong antimicrobial activity against Gram-positive bacteria. Both products are generally available as salts to facilitate their application in feed. In this study, the results showed that DIC was the most effective against the Gram-positive bacteria tested, followed by DIC50:50 and DIC70:30, the sodium butyrate-based products. As expected, a higher concentration of MCFA in the tested product was associated with a higher inhibitory and bactericidal activity. Further studies would be required to better understand these interactions as well as in vivo studies to demonstrate the effects on microbial populations.


2019 ◽  
Vol 21 (2) ◽  
pp. 125
Author(s):  
U.B. Issayeva ◽  
G.S. Akhmetova ◽  
U.M. Datkhayev ◽  
M.T. Omyrzakov ◽  
K.D. Praliyev ◽  
...  

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.


2020 ◽  
Vol 13 (7) ◽  
pp. 3390-3397
Author(s):  
Regina Kemunto Mayaka ◽  
Alice Wanjiku Njue ◽  
Moses Kiprotich Langat ◽  
Peter Kiplagat Cheplogoi ◽  
Josiah Ouma Omolo

The emergence of antibiotic resistant pathogens has continuously increased, leading to a growing worldwide health threat due to infectious diseases. And therefore in our search for antibacterial and antifungal compounds from the polypore Ganoderma adspersum, the dried, ground fruiting bodies of G. adspersum were extracted with methanol and solvent removed in a rotary evaporator. The extract was suspended in distilled water, then partitioned using ethyl acetate solvent to obtain an ethyl acetate extract. The extract was fractionated and purified using column chromatographic method and further purification on sephadex LH20. The chemical structures were determined on the basis of NMR spectroscopic data from 1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, and NOESY experiments. Antimicrobial activity against clinically important bacterial and fungal strains was assessed and zones of inhibition were recorded. Compound (1), ergosta-7,22-dien-3-one weakly inhibited the growth of Gram positive bacteria Streptococcus pneumonia and a fungus Cryptococcus neoformans. Compounds ergosta-7,22-dien-3-ol (2) and ergosta-5,7,22-trien-3-ol (3) also inhibited gram positive Streptococcus pyogenes bacteria.Keywords: Polypores, steroid compounds, antimicrobial activity.


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