Evaluation of topologically distinct constrained antimicrobial peptides with broad-spectrum antimicrobial activity

2018 ◽  
Vol 16 (32) ◽  
pp. 5764-5770 ◽  
Author(s):  
Fang Yuan ◽  
Yuan Tian ◽  
Weirong Qin ◽  
Jingxu Li ◽  
Dan Yang ◽  
...  

Conformationally constrained peptides with either α-helical or β-hairpin conformations, possessing different topological distribution of hydrophobic and hydrophilic residues, displayed distinct anti-microbial activity towards Gram positive and Gram negative bacteria and fungi.

2015 ◽  
Vol 21 (4) ◽  
pp. 191-194 ◽  
Author(s):  
Oussama Cherif ◽  
Fatma Masmoudi ◽  
Fatma Allouche ◽  
Fakher Chabchoub ◽  
Mohamed Trigui

AbstractAn efficient synthesis of new pyrrolopyrimidinones 3a-d and isoxazolopyrimidinones 4a-c from the respective aminocyanopyrroles 1a-d and aminocyanoisoxazoles 2a-c is presented. The synthesized compounds were screened for antimicrobial activity against a panel of bacteria and fungi. Compound 4c exhibits remarkable activity against a broad spectrum of Gram-positive and Gram-negative bacteria and pathogenic fungi.


Author(s):  
Nilesh M. Thumar ◽  
Ankur A. Kaneria ◽  
Milan Vadodaria ◽  
Kartik Ladva

A convenient synthesis of substituted Pyrazolo[1,5-a]pyrimidine was carried out by the reaction of different ketene dithioacetals with different aromatic amine in isopropanol in the presence of potassium carbonate. The newly synthesized compound were characterized by1H NMR, IR, Mass and screened for their antimicrobial activity against various strains of bacteria and fungi. From the synthesized different NCEs, compounds 8a, 8d and 8e are broad spectrum drug which can inhibit the growth of gram positive, gram negative bacteria and fungi.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2793 ◽  
Author(s):  
Ameen Abu-Hashem

Substituted-6-methyl-1-thioxo-1,2-dihydro-3H-furo[3,2-g]pyrimido[1,6-a]quinazolin-3-ones (5a,b) were synthesized from condensation of visnagenone (2a) or khellinone (2b) with 6-amino-thiouracil (3) in dimethylformamide or refluxing of (4a) or (4b) in dimethylformamide. Hence, compounds (5a,b) were used as the starting materials for preparing many new heterocyclic compounds such as; furo[3,2-g]pyrimido[1,6-a]quinazoline (6a,b), furo[3,2-g]thiazolo[2′,3′:2,3]pyrimido[1,6-a]quinazolinone (7a,b), substituted-benzylidene-furo[3,2-g]thiazolo[2′,3′:2,3]pyrimido[1,6-a]quinazoline-3,5-dione (8a–f), 3-oxo-furo[3,2-g]pyrimido[1,6-a]quinazoline-pentane-2,4-dione (9a,b), 1-(pyrazole)-furo[3,2-g]pyrimido[1,6-a]quinazolinone (10a,b), 2-(oxo or thioxo)-pyrimidine-furo[3,2-g]pyrimido[1,6-a]quinazolinone (11a–d), 1-(methylthio)-furo[3,2-g]pyrimido[1,6-a]quinazolinone (12a,b), 1-(methyl-sulfonyl)-furo[3,2-g]pyrimido[1,6-a]quinazolinone (13a,b) and 6-methyl-1-((piperazine) or morpholino)-3H-furo[3,2-g]pyrimido[1,6-a]quinazolin-3-one (14a–d). The structures of the prepared compounds were elucidated on the basis of spectral data (IR, 1H-NMR, 13C-NMR, MS) and elemental analysis. Antimicrobial activity was evaluated for the synthesized compounds against Gram-positive, Gram-negative bacteria and fungi. The new compounds, furothiazolo pyrimido quinazolines 8a–f and 11a–d displayed results excellent for growth inhibition of bacteria and fungi.


2021 ◽  
Vol 10 (2) ◽  
pp. 14-23
Author(s):  
Sanja Kokanov ◽  
Milan Nikolić ◽  
Irena Novaković ◽  
Tamara Todorović ◽  
Nenad Filipović

(Thiazolyl-2-yl)hydrazones (THs) are a group of organic compounds containing both hydrazone and 1,3-thiazole pharmacophores present in many approved drugs. They have been investigated greatly in recent years due to potent anticancer, antibacterial, antifungal, antituberculosis, anti-inflammatory, and antiparasitic activities. In this study, one pyridine-based and two quinoline-based, novel THs were synthesized and characterized by elemental analysis, Fourier-transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). The antimicrobial activity of the compounds was tested against five Gram-positive and five Gram-negative bacteria, as well as against three fungi. The antioxidant capacity of the compounds was tested in six antioxidative assays. The results showed that quinoline-based THs were more active against tested Gram-negative bacteria and fungi strains than pyridine-based compounds. All the compounds showed excellent antioxidative activity comparable to or greater than the used standards (vitamin C and Trolox). Absorption, distribution, metabolism, excretion, and toxicity (ADMET) parameters were calculated in-silico. Results pointed to promising good pharmacokinetics profiles of investigated compounds, especially 2-quinoline carboxaldehyde-based compound, which can be a lead drug candidate.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Mark Austin Hanson ◽  
Anna Dostálová ◽  
Camilla Ceroni ◽  
Mickael Poidevin ◽  
Shu Kondo ◽  
...  

Antimicrobial peptides (AMPs) are host-encoded antibiotics that combat invading microorganisms. These short, cationic peptides have been implicated in many biological processes, primarily involving innate immunity. In vitro studies have shown AMPs kill bacteria and fungi at physiological concentrations, but little validation has been done in vivo. We utilized CRISPR gene editing to delete most known immune-inducible AMPs of Drosophila, namely: 4 Attacins, 2 Diptericins, Drosocin, Drosomycin, Metchnikowin and Defensin. Using individual and multiple knockouts, including flies lacking these ten AMP genes, we characterize the in vivo function of individual and groups of AMPs against diverse bacterial and fungal pathogens. We found that Drosophila AMPs act primarily against Gram-negative bacteria and fungi, contributing either additively or synergistically. We also describe remarkable specificity wherein certain AMPs contribute the bulk of microbicidal activity against specific pathogens, providing functional demonstrations of highly specific AMP-pathogen interactions in an in vivo setting.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Gabrielle Sherella Dijksteel ◽  
Peter H. Nibbering ◽  
Magda M. W. Ulrich ◽  
Esther Middelkoop ◽  
Bouke K. H. L. Boekema

Abstract Background Accurate determination of the efficacy of antimicrobial agents requires neutralization of residual antimicrobial activity in the samples before microbiological assessment of the number of surviving bacteria. Sodium polyanethol sulfonate (SPS) is a known neutralizer for the antimicrobial activity of aminoglycosides and polymyxins. In this study, we evaluated the ability of SPS to neutralize residual antimicrobial activity of antimicrobial peptides [SAAP-148 and pexiganan; 1% (wt/v) in PBS], antibiotics [mupirocin (Bactroban) and fusidic acid (Fucidin) in ointments; 2% (wt/wt))] and disinfectants [2% (wt/wt) silver sulfadiazine cream (SSD) and 0.5% (v/v) chlorhexidine in 70% alcohol]. Methods Homogenates of human skin models that had been exposed to various antimicrobial agents for 1 h were pipetted on top of Methicillin-resistant Staphylococcus aureus (MRSA) on agar plates to determine whether the antimicrobial agents display residual activity. To determine the optimal concentration of SPS for neutralization, antimicrobial agents were mixed with PBS or increasing doses of SPS in PBS (0.05–1% wt/v) and then 105 colony forming units (CFU)/mL MRSA were added. After 30 min incubation, the number of viable bacteria was assessed. Next, the in vitro efficacy of SAAP-148 against various gram-positive and gram-negative bacteria was determined using PBS or 0.05% (wt/v) SPS immediately after 30 min incubation of the mixture. Additionally, ex vivo excision wound models were inoculated with 105 CFU MRSA for 1 h and exposed to SAAP-148, pexiganan, chlorhexidine or PBS for 1 h. Subsequently, samples were homogenized in PBS or 0.05% (wt/v) SPS and the number of viable bacteria was assessed. Results All tested antimicrobials displayed residual activity in tissue samples, resulting in a lower recovery of surviving bacteria on agar. SPS concentrations at ≥0.05% (wt/v) were able to neutralize the antimicrobial activity of SAAP-148, pexiganan and chlorhexidine, but not of SSD, Bactroban and Fucidin. Finally, SPS-neutralization in in vitro and ex vivo efficacy tests of SAAP-148, pexiganan and chlorhexidine against gram-positive and gram-negative bacteria resulted in significantly higher numbers of CFU compared to control samples without SPS-neutralization. Conclusions SPS was successfully used to neutralize residual activity of SAAP-148, pexiganan and chlorhexidine and this prevented an overestimation of their efficacy.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Anwar Ali Chandio ◽  
Ayaz Ali Memon ◽  
Shahabuddin Memon ◽  
Fakhar N. Memon ◽  
Qadeer Khan Panhwar ◽  
...  

Present study deals with the synthesis of the p-tert-butylcalix[4]arene diamide derivative as ligand (L) and its Fe3+ complex, followed by its characterization using TLC and FT-IR, while UV-Vis and Job’s plot study were performed for complex formation. Antimicrobial activity of the derivative (L) and its metal complex was carried out by the disc diffusion method against bacteria (Escherichia coli and Staphylococcus albus) and fungi (R. stolonifer). Different concentrations of the derivative (L) (6, 3, 1.5, 0.75, and 0.37 μg/mL) and its Fe3+ complex were prepared, and Mueller–Hinton agar was used as the medium for the growth of microorganisms. Six successive dilutions of the derivative (L) and Fe3+ complex were used against microorganisms. Two successive dilutions (6 and 3 μg/mL) of the derivative (L) showed antibacterial action against both Gram-positive and Gram-negative bacteria. In addition, three successive dilutions (6, 3, and 1.5 μg/mL) of the derivative (L) showed antifungal activity. However, all of six dilutions of the Fe3+ complex showed antimicrobial activity. Derivative (L) showed 3 and 1.5 μg/mL minimum inhibitory concentrations (MIC) against bacteria and fungi, respectively. On the contrary, its Fe3+ complex showed 0.37 μg/mL value of MIC against bacteria and fungi. Hence, Fe3+ complex of the derivative (L) was found to be a more effective antimicrobial agent against selected bacteria and fungi than the diamide derivative (L).


2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Pattusamy Nithya ◽  
Fazlur-Rahman Nawaz Khan ◽  
Selvaraj Roopan ◽  
Uma Shankar ◽  
Jong Jin

AbstractAn efficient and environmentally benign one-pot method for the synthesis of 1-methyl-2,6-diarylpiperidin-4-ones using montmorillonite K-10 as a catalyst has been developed. Antimicrobial activity of the compounds has been tested against selected representatives of Gram-positive and Gram-negative bacteria and fungi.


2017 ◽  
Vol 82 (5) ◽  
pp. 495-508 ◽  
Author(s):  
Aleksandra Bozic ◽  
Nenad Filipovic ◽  
Irena Novakovic ◽  
Snezana Bjelogrlic ◽  
Jasmina Nikolic ◽  
...  

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide?water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone.


1970 ◽  
Vol 34 (2) ◽  
pp. 201-203 ◽  
Author(s):  
Mohammad Shahriar

Successive extraction of the dried rhizomes of Curcuma zedoaria Rocs. provided n-hexane, ethyl acetate and methanol extracts. The antimicrobial activity of the different extracts of Curcuma zedoaria was investigated at an initial dose of 500 μg/disc against gram positive, gram negative bacteria and fungi. The methanol extract of the herb showed significant activity against some tested gram negative bacteria. The ethyl acetate extract exhibited moderate activity while the n-hexane showed little activity against some gram negative bacteria.Key words: Curcuma zedoaria; Rhizomes; Antimicrobial activity DOI: 10.3329/jbas.v34i2.6867Journal of Bangladesh Academy of Sciences, Vol. 34, No. 2, 201-203, 2010


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