scholarly journals Microwave Synthesis, Characterization, and Antimicrobial Activity of Some Novel Isatin Derivatives

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ayman El-Faham ◽  
Wael N. Hozzein ◽  
Mohammad A. M. Wadaan ◽  
Sherine N. Khattab ◽  
Hazem A. Ghabbour ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Carboxylic Acid ◽  
Fungal Pathogens ◽  
Biologically Active ◽  
Moderate Activity ◽  
Gram Positive ◽  
X Ray Crystallography ◽  
Gram Positive Bacteria ◽  
Bacteria And Fungi ◽  
Isatin Derivatives

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.

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 Antimicrobial Activity of Ultrasonic Extracts of Two Chemotypes of Thymus serpyllum L. of Central Kazakhstan and their Polyphenolic Profiles

2021 ◽  
Vol 9 (A) ◽  
pp. 61-67
Author(s):  
Svetlana Ivasenko ◽  
Perizat Orazbayeva ◽  
Krystyna Skalicka–Wozniak ◽  
Agnieszka Ludwiczuk ◽  
Alexandr Marchenko ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Wide Spectrum ◽  
Biological Properties ◽  
Climatic Conditions ◽  
Biologically Active ◽  
Gram Positive Bacteria ◽  
Quantitative Content ◽  
Two Samples ◽  
Thymus Serpyllum ◽  
Bacteria And Fungi

BACKGROUND: The medicinal plant of Thymus serpyllum L. in nature, depending on the geographical region, climatic conditions, and growing environment, is represented with some chemotypes. Composition and quantitative content of the basic groups of the biologically active substances can be differed, and thus their biological properties are also various. AIM: The aim of the study was to determine possibility of the using the ultrasonic extracts of two chemotypes of T. serpyllum L. of Central Kazakhstan as an antimicrobial agent against test strains of microorganisms. MATERIALS AND METHODS: Two samples of T. serpyllum were extracted with 70% ethanol using ultrasound. The polyphenol content of the ultrasound extracts was determined using the LC-ultraviolet-ESI- tandem mass spectrometry technique. A study of an antimicrobial activity of the ultrasonic extracts was performed with eight strains of Gram-positive bacteria, six strains of Gram-negative bacteria, and four cultures of fungi. RESULTS: The ultrasonic extracts of two chemotypes of T. serpyllum L. are similar in composition of phenolic compounds but differ in a quantitative content of phenolic acids and flavonoids, except for a rosmarinic acid. The ultrasonic extracts have a wide spectrum of antimicrobial activity, exhibit the bactericidal or bacteriostatic activity against all tested bacteria and fungi at a concentration of 0.0625–20 mg/ml, but differ in their strength of action against test strains of microorganisms. CONCLUSION: The ultrasonic extracts of two chemotypes of T. serpyllum L. of Central Kazakhstan can be considered as a potential drug with a wide spectrum of antimicrobial activity. The results of chromatographic analysis will be used for standardization of a drug.

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.

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 Novel (+)-Neoisopulegol-Based O-Benzyl Derivatives as Antimicrobial Agents

2021 ◽  
Vol 22 (11) ◽  
pp. 5626
Author(s):  
Tam Minh Le ◽  
Thu Huynh ◽  
Fatima Zahra Bamou ◽  
András Szekeres ◽  
Ferenc Fülöp ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Substituent Effects ◽  
Moderate Activity ◽  
Gram Negative Bacteria ◽  
Gram Positive Bacteria ◽  
Urgent Task ◽  
Bacteria And Fungi ◽  
Antibacterial And Antifungal ◽  
Derivatives Of

Discovery of novel antibacterial agents with new structures, which combat pathogens is an urgent task. In this study, a new library of (+)-neoisopulegol-based O-benzyl derivatives of aminodiols and aminotriols was designed and synthesized, and their antimicrobial activity against different bacterial and fungal strains were evaluated. The results showed that this new series of synthetic O-benzyl compounds exhibit potent antimicrobial activity. Di-O-benzyl derivatives showed high activity against Gram-positive bacteria and fungi, but moderate activity against Gram-negative bacteria. Therefore, these compounds may serve a good basis for antibacterial and antifungal drug discovery. Structure–activity relationships were also studied from the aspects of stereochemistry of the O-benzyl group on cyclohexane ring and the substituent effects on the ring system.

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 Preliminary Biological Activity Evaluation of New N- Substituted Phthalimide Derivatives

2020 ◽  
Vol 29 (1) ◽  
pp. 247-252
Author(s):  
Halah A. Sahib ◽  
Mohammed H. Mohammed
Keyword(s):  
Antimicrobial Activity ◽  
Methyl Ester ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Ft Ir ◽  
Bacteria And Fungi ◽  
Phenylalanine Methyl Ester

A A new series of bases of Schiff (H2-H4) derived from phthalic anhydrideweresynthesized. These Schiff bases were prepared by the reaction of different amines (tyrosine methyl ester, phenylalanine methyl ester, and isoniazid) with the phthalimide derived aldehyde with the aid of glacial acetic acid or triethylamine ascatalysts. All the synthesized compounds were characterized by (FT-IR and 1HNMR) analyses and were in vitro evaluated for their antimicrobial activity against six various kinds of microorganisms. All the synthesized compounds had been screened for their antimicrobial activity against two Gram-positive bacteria “Staph. Aureus, and Bacillus subtilis”, two Gram-negative bacteria “Escherichia coli, and Klebsiella pneumoniae”, and two fungi species “Candida tropicalis and Candida albicans” using concentrations of 62.5, 125 and 250 µg\mLof derivative in dimethyl sulfoxide(DMSO). All the synthesized compounds showed no activity at all against Gram-positive bacteria, for Gram-negative bacteria and fungi they showed moderate or no activity except compound H1revealedhigh antifungal activityagainstCandida tropicalisat concentrations 125 and 250 µg\ mL. Keywords: Schiff base, phthalic anhydride, antimicrobial.  

scholarly journals Comparison of Antimicrobial Activity of Chitosan Nanoparticles against Bacteria and Fungi

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 769
Author(s):  
Yage Xing ◽  
Xiaomin Wang ◽  
Xunlian Guo ◽  
Ping Yang ◽  
Jinze Yu ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Fungal Pathogens ◽  
Chitosan Nanoparticles ◽  
Gram Negative Bacteria ◽  
Damping Off ◽  
Absorption Intensity ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Antifungal Effects ◽  
Bacteria And Fungi

Chitosan nanoparticles (CSNPs) have attracted wide interest; however, there has been no substantial information about a direct comparison of the antimicrobial activity of CSNPs on bacteria and fungi. Thus, in this study, simple, economically feasible CSNPs were synthesized and assessed for their antimicrobial activity. This investigation indicated that the coordination inducing effect of CSNPs could dissociate the tryptophan (Trp) and tyrosine (Tyr) residue groups on the peptide chain of the bovine serum albumin (BSA) molecule, thereby increasing the absorption intensity. The growth of E. coli and S. aureus could be completely inhibited when the concentration of CSNPs in the solution was higher than 0.6 mg/mL. The CSNPs showed more potent antibacterial activity against Gram-negative bacteria (E. coli) than against Gram-positive bacteria (S. aureus). In addition, the CSNPs were effective at initiating cellular leakage of fungal mycelia and damping off fungal pathogens, and their antifungal effects were stronger on P. steckii than on A. oryzae. Furthermore, the antimicrobial activity of the CSNPs was found to be more effective against bacteria than against fungi. This study thus ascertained the antimicrobial activity of synthesized CSNPs against different microorganisms, as well as their different degrees of inhibition.

scholarly journals Synthesis and Evaluation of Some Coumarin Based Schiff's Bases as Potential Antimicrobial Agents'

2012 ◽  
Vol 9 (4) ◽  
pp. 2079-2088 ◽  
Author(s):  
Vishakha Bansode ◽  
Meenakshi N. Deodhar
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
H Nmr ◽  
Nmr Data ◽  
Bacteria And Fungi

A series of the title compounds 3-(4-(4, 5-dihydro-5-(substituted phenyl)-1H-3-pyrazolyl) phenylimino) methyl)-4-chloro-2H-chromen-2-one 5(a-g) have been synthesized. These compounds were characterized on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activityin vitroagainst gram positive bacteria, gram negative bacteria and fungi. The compound (5b) was found to be the most active with MIC of 20 µg/ml against all the tested organisms.

scholarly journals Screening Antimicrobial Activity of Nickel Nanoparticles Synthesized Using Ocimum sanctum Leaf Extract

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Chitra Jeyaraj Pandian ◽  
Rameshthangam Palanivel ◽  
Solairaj Dhanasekaran
Keyword(s):  
Antimicrobial Activity ◽  
Leaf Extract ◽  
Nickel Nanoparticles ◽  
Ocimum Sanctum ◽  
Ros Generation ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Bacteria And Fungi

Antimicrobial efficacy of nickel nanoparticles synthesized using leaf extract of Ocimum sanctum (NiGs) was investigated against pathogenic Gram-negative (E. coli, K. pneumoniae, and S. typhi), Gram-positive (B. subtilis, S. epidermidis) bacteria and fungi (C. albicans, C. tropicalis, A. fumigatus, A. clavatus, and A. niger). 100 µg/mL NiGs showed maximum antimicrobial activity against tested pathogens compared to leaf extract and antibiotics. E. coli (25 mm) and C. albicans (23 mm) exhibited higher zone of inhibition at 100 µg/mL NiGs. MIC, MBC, and MFC values of NiGs against all tested pathogens ranged between 25 and 50 µg/mL. Growth of bacterial and fungal cells (105 cfu/mL) was completely inhibited at 50 µg/mL NiGs. E. coli and C. albicans have showed strong antimicrobial activity with 81% and 50% reactive oxygen species (ROS) production, 30 and 16 µg/mL protein leakage, and 95 and 82 U/L LDH leakages, respectively. Gram-negative bacteria and Candida species showed more sensitivity to NiGs at all concentrations tested (25–100 µg/mL) than Gram-positive bacteria and Aspergillus species, respectively. Microbial growth in the presence of NiGs and ascorbic acid confirmed the involvement of ROS in antimicrobial activity. Hence, NiGs induced ROS generation was attributed to the protein and LDH leakage from microbial membranes.

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