scholarly journals Wide-Antimicrobial Spectrum of Picolinium Salts

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2254 ◽  
Author(s):  
Sarka Salajkova ◽  
Marketa Benkova ◽  
Jan Marek ◽  
Radek Sleha ◽  
Lukas Prchal ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activity ◽  
Mammalian Cells ◽  
Alkyl Chain ◽  
Critical Micellar Concentration ◽  
Antimicrobial Compounds ◽  
Methyl Substituent ◽  
Antimicrobial Spectrum ◽  
Alkyl Chains ◽  
Low Cytotoxicity

Nosocomial infections, which greatly increase morbidity among hospitalized patients, together with growing antibiotic resistance still encourage many researchers to search for novel antimicrobial compounds. Picolinium salts with different lengths of alkyl chains (C12, C14, C16) were prepared by Menshutkin-like reaction and evaluated with respect to their biological activity, i.e., lipophilicity and critical micellar concentration. Picolinium salts with C14 and C16 side chains achieved similar or even better results when in terms of antimicrobial efficacy than benzalkoniums; notably, their fungicidal efficiency was substantially more potent. The position of the methyl substituent on the aromatic ring does not seem to affect antimicrobial activity, in contrast to the effect of length of the N-alkyl chain. Concurrently, picolinium salts exhibited satisfactory low cytotoxicity against mammalian cells, i.e., lower than that of benzalkonium compounds, which are considered as safe.

scholarly journals Brevinin-2GHk from Sylvirana guentheri and the Design of Truncated Analogs Exhibiting the Enhancement of Antimicrobial Activity

Antibiotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 85 ◽  
Author(s):  
Guanzhu Chen ◽  
Yuxi Miao ◽  
Chengbang Ma ◽  
Mei Zhou ◽  
Zhanzhong Shi ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Mammalian Cells ◽  
Structural Changes ◽  
Structural Characteristics ◽  
Helical Conformation ◽  
Skin Secretion ◽  
Mature Peptide ◽  
Diverse Range ◽  
Low Cytotoxicity ◽  
Α Helix

Brevinins are an important antimicrobial peptide (AMP) family discovered in the skin secretions of Ranidae frogs. The members demonstrate a typical C-terminal ranabox, as well as a diverse range of other structural characteristics. In this study, we identified a novel brevinin-2 peptide from the skin secretion of Sylvirana guentheri, via cloning transcripts, and identifying the expressed mature peptide, in the skin secretion. The confirmed amino acid sequence of the mature peptide was designated brevinin-2GHk (BR2GK). Moreover, as a previous study had demonstrated that the N-terminus of brevinin-2 is responsible for exerting antimicrobial activity, we also designed a series of truncated derivatives of BR2GK. The results show that the truncated derivatives exhibit significantly improved antimicrobial activity and cytotoxicity compared to the parent peptide, except a Pro14 substituted analog. The circular dichroism (CD) analysis of this analog revealed that it did not fold into a helical conformation in the presence of either lipopolysaccharides (LPS) or TFE, indicating that position 14 is involved in the formation of the α-helix. Furthermore, three more analogs with the substitutions of Ala, Lys and Arg at the position 14, respectively, revealed the influence on the membrane disruption potency on bacteria and mammalian cells by the structural changes at this position. Overall, the N-terminal 25-mer truncates demonstrated the potent antimicrobial activity with low cytotoxicity.

scholarly journals Antimicrobial Peptide CMA3 Derived from the CA-MA Hybrid Peptide: Antibacterial and Anti-inflammatory Activities with Low Cytotoxicity and Mechanism of Action in Escherichia coli

2015 ◽  
Vol 60 (1) ◽  
pp. 495-506 ◽  
Author(s):  
Jong-kook Lee ◽  
Chang Ho Seo ◽  
Tudor Luchian ◽  
Yoonkyung Park
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Antimicrobial Peptide ◽  
Blood Cells ◽  
Mammalian Cells ◽  
White Blood Cells ◽  
Raw 264.7 Cells ◽  
Content Type ◽  
Anti Inflammatory ◽  
Low Cytotoxicity

ABSTRACTCA-MA is a hybrid antimicrobial peptide (AMP) derived from two naturally occurring AMPs, cecropin A and magainin 2. CA-MA shows strong antimicrobial activity against Gram-negative and Gram-positive bacteria but also exhibits cytotoxicity toward mammalian cells. Our objective was to identify CA-MA analogues with reduced cytotoxicity by systematic replacement of amino acids with positively charged R groups (His and Lys), aliphatic R groups (Leu), or polar R groups (Glu). Among the CA-MA analogues studied (CMA1 to -6), CMA3 showed the strongest antimicrobial activity, including against drug-resistantEscherichia coliandPseudomonas aeruginosastrains isolated from hospital patients. CMA3 appeared to act by inducing pore formation (toroidal model) in the bacterial membrane. In cytotoxicity assays, CMA3 showed little cytotoxicity toward human red blood cells (hRBCs) or HaCaT cells. Additionally, no fluorescence was released from small or giant unilamellar vesicles exposed to 60 μM CMA3 for 80 s, whereas fluorescence was released within 35 s upon exposure to CA-MA. CMA3 also exerted strong lipopolysaccharide (LPS)-neutralizing activity in RAW 264.7 cells, and BALB/c mice exposed to LPS after infection byEscherichia colishowed improved survival after administration of one 0.5-mg/kg of body weight or 1-mg/kg dose of CMA3. Finally, in a mouse model of septic shock, CMA3 reduced the levels of proinflammatory factors, including both nitric oxide and white blood cells, and correspondingly reduced lung tissue damage. This study suggests that CMA3 is an antimicrobial/antiendotoxin peptide that could serve as the basis for the development of anti-inflammatory and/or antimicrobial agents with low cytotoxicity.

Polypyridyl iron(III) complexes containing long alkyl chains: Synthesis, characterization, DFT calculations and biological activity.

2021 ◽  
Author(s):  
Marcelo Melotti ◽  
Matheus dos Santos Sartori Paqui ◽  
Andre Luiz Amorim ◽  
Carla Peres de Paula ◽  
Marina Campos Rocha ◽  
...  
Keyword(s):  
Biological Activity ◽  
Dft Calculations ◽  
Metal Complexes ◽  
Alkyl Chain ◽  
Alkyl Chains ◽  
Polypyridyl Ligand ◽  
Iron Salts ◽  
Long Alkyl Chain

A polypyridyl ligand functionalized with a long alkyl chain (LC10) was prepared. Reaction of LC10 with selected iron salts of different stoichiometries formed two metal complexes: [Fe(LC10)(Cl)3] (1) and [Fe(LC10)2](ClO4)3...

scholarly journals Synthesis and Antimicrobial Activity of Quinazolinone Conjugated Peptides

2010 ◽  
Vol 7 (2) ◽  
pp. 449-456 ◽  
Author(s):  
G. P. Suresha ◽  
K. C. Prakasha ◽  
Wethroe Kapfo ◽  
D. Channe Gowda
Keyword(s):  
Antimicrobial Activity ◽  
Chain Length ◽  
Alkyl Chain ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Antimicrobial Compounds ◽  
Bacterial Strains ◽  
Butanoic Acid ◽  
Disc Diffusion Method ◽  
Structure Activity

Antimicrobial compounds were synthesized by coupling 4-(4-oxo-3,4-dihydroquinazolin-2-yl) butanoic acid with VP, GVP, VGVP and GVGVP peptides. Antimicrobial activities of the synthesized compounds were performed against various bacterial strains by disc diffusion method. The structure activity relationship was evaluated with respect to hydrophobicity, polarity, chain length of peptides and alkyl chain length of quinazolinone. Correlations of analogs with respect to their antimicrobial activity in comparison with conventional drugs and probable mechanism for the activity were discussed.

Quantitative Relationships Between Structure, Aggregation Properties and Antimicrobial Activity of Quaternary Ammonium Bolaamphiphiles

1995 ◽  
Vol 60 (7) ◽  
pp. 1213-1228 ◽  
Author(s):  
Magdaléna Pavlíková ◽  
Ivan Lacko ◽  
Ferdinand Devínský ◽  
Dušan Mlynarčík
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activity ◽  
Quaternary Ammonium ◽  
Hydrocarbon Chain ◽  
Critical Micellar Concentration ◽  
Bilinear Model ◽  
Qsar Analysis ◽  
Inhibition Concentration ◽  
Chromatographic Parameter ◽  
The Relationship

QSAR analysis employing Kubinyi's bilinear model was applied to examine the relationship between the structure (characterized by the lengths of the terminal hydrocarbon chain, m, and of the hydrocarbon spacer chain, y), lipophilicity (characterized by the chromatographic parameter Rm and aggregation properties expressed through the critical micellar concentration cK), and antimicrobial activity (characterized by the minimum inhibition concentration, MIC) of quaternary ammonium bolaamphiphiles. The log cK = f(m) dependence was found to be linear whereas the log (1/MIC) = f(m), log (1/MIC) = f(y), log (1/MIC) = f (log cK) and log (1/MIC) = f(Rm) dependences were nonlinear. The effect of the hydrophobic terminal chains (m) and of the hydrophobic spacer chain (y) on the aggregation properties and on the biological activity of the substances was studied.

Screening and antimicrobial activity of actinomycetes isolated from the rhizosphere of Clitoria ternatea

2016 ◽  
Vol 1 (01) ◽  
Author(s):  
Vemavarapu Bhaskara Rao ◽  
Kandlagunta Guru Prasad ◽  
Krishna Naragani ◽  
Vijayalakshmi Muvva
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Calcium Carbonate ◽  
Rhizosphere Soil ◽  
Soil Samples ◽  
Antimicrobial Spectrum ◽  
Clitoria Ternatea ◽  
Primary Screening

The air dried rhizosphere soil samples pretreated with calcium carbonate was employed for the isolation of actinomycete strains. Serial dilution plate technique was used for the isolation of actinomycetes. A total of 20 actinomycete strains designated as BS1-BS20 were isolated from the rhizosphere of medicinal plant Clitoria ternatea. All the 20 strains were subjected to primary screening for antimicrobial activity. Among the 20 strains screened, 10 strains exhibited high antimicrobial spectrum against Staphylococcus aureus, Escherichia coli and Candida albicans.

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>

Complexes of Cu (II) with a-Ketoglutaric Acid and 1- (o-tolyl) Biguanide Synthesis, characterization and biological Activity

2019 ◽  
Vol 70 (10) ◽  
pp. 3603-3610
Author(s):  
Madalina Mihalache ◽  
Cornelia Guran ◽  
Aurelia Meghea ◽  
Vasile Bercu ◽  
Ludmila Motelica ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Biological Activity ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Copper Complexes ◽  
Substrate Adhesion ◽  
Inert Substrate

The three copper complexes having a-ketoglutaric acid (H2A) and 1- (o-tolyl) biguanide (TB) ligands have been synthesized and characterized. The proposed formulas for these complexes are: [Cu(TB)(HA)]Cl (C1), [Cu(TB)(HA)CH3COO]�H2O (C2) and [Cu(TB)(HA)](NO3) (C3) where HA represents deprotonated H2A. The complexes obtained were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, antifungal activity on Candida albicans ATCC 10231 and antitumor activity on HeLa tumor cells. Due to the antitumor, antifungal, antimicrobial activity and inhibition of inert substrate adhesion, complexes synthesized could be used for potential therapeutic applications.

Synthesis and Structure−Activity Relationship Studies of N-monosubstituted Aroylthioureas as Urease Inhibitors

2020 ◽  
Vol 16 ◽  
Author(s):  
Wei-Wei Ni ◽  
Hai-Lian Fang ◽  
Ya-Xi Ye ◽  
Wei-Yi Li ◽  
Li Liu ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Mammalian Cells ◽  
Intact Cell ◽  
Linear Regression Analysis ◽  
Positive Control ◽  
Acetohydroxamic Acid ◽  
Urease Inhibitors ◽  
Ic50 Value ◽  
Ic50 Values ◽  
Low Cytotoxicity

Background: Thiourea is a classical urease inhibitor usually as a positive control, and many N,N`-disubstituted thioureas have been determined as urease inhibitors. However, due to steric hindrance, N,N`-disubstituted thiourea motif could not bind urease as thiourea. On the contrary, N-monosubstituted thioureas with a tiny thiourea motif could theoretically bind into the active pocket as thiourea. Objective: A series of N-monosubstituted aroylthioureas were designed and synthesized for evaluation as urease inhibitors. Methods: Urease inhibition was determined by the indophenol method and IC50 values were calculated using computerized linear regression analysis of quantal log dose-probit functions. The kinetic parameters were estimated viasurface plasmon resonance (SPR) and by nonlinear regression analysis based on the mixed type inhibition model derived from Michaelis-Menten kinetics. Results: Compounds b2, b11and b19 reversibly inhibited urease with a mixed mechanism, and showed excellent potency against both cell-free urease and urease in intact cell, with IC50 values being 90-to 450-fold and 5-to 50-fold lower than the positive control acetohydroxamic acid, respectively. The most potent compound b11 showed IC50 value of 0.060 ±0.004μM against cell-free urease, which bound to urea binding site with a very low KDvalue (0.420±0.003nM) and a very long residence time (6.7 min). Compound b11was also demonstrated having very low cytotoxicity to mammalian cells. Conclusion: These results revealed that N-monosubstituted aroylthioureas clearly bind the active site of urease as expected, and represent a new class of urease inhibitors for the development of potential therapeutics against infections caused by ure-ase-containing pathogens.

Alkyl-chain disorder in tetraisohexylammonium bromide

2012 ◽  
Vol 68 (4) ◽  
pp. o152-o155 ◽  
Author(s):  
Malcolm A. Kelland ◽  
Amber L. Thompson
Keyword(s):  
Crystal Structure ◽  
Crystal Growth ◽  
Alkyl Chain ◽  
Growth Inhibitor ◽  
Ammonium Cation ◽  
Asymmetric Unit ◽  
Bromide Anion ◽  
Alkyl Chains ◽  
Hydrate Crystal ◽  
Structure Ii Clathrate Hydrate

Tetraisohexylammonium bromide [systematic name: tetrakis(4-methylpentyl)azanium bromide], C24H52N+·Br−, is a powerful structure II clathrate hydrate crystal-growth inhibitor. The crystal structure, in the space groupP3221, contains one ammonium cation and one bromide anion in the asymmetric unit, both on general positions. At 100 K, the ammonium cation exhibits one ordered isohexyl chain and three disordered isohexyl chains. At 250 K, all four isohexyl chains are disordered. In an effort to reduce the disorder in the alkyl chains, the crystal was thermally cycled, but the disorder remained, indicating that it is dynamic in nature.

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