scholarly journals Antimicrobial Activity of Undecan-x-Ones (x = 2-4)

2010 ◽  
Vol 59 (4) ◽  
pp. 301-306 ◽  
Author(s):  
ALINA KUNICKA-STYCZYŃSKA ◽  
JULIA GIBKA

As a continuation of our research on the biological activity of undecan-x-ones (x = 2-4), their antimicrobial activity towards bacteria Escherichia coli and Bacillus subtilis, yeast Candida mycoderma and mould Aspergillus niger, was investigated. The population viability of the tested microbial strains in the presence of undecan-x-ones was determined by the impedimetric and agar disc diffusion methods. Undecan-x-ones showed low antibacterial activity towards both Gram-positive and Gram-negative bacteria. Undecan-2-one and undecan-3-one exhibited high activity towards C. mycoderma. All undecan-x-ones expressed the strongest effect on A. niger. The tests have proven that due to high fungistatic activity undecan-x-ones can be used to aid stabilization of food and cosmetic matrices.

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2374
Author(s):  
Paula C. Alves ◽  
Patrícia Rijo ◽  
Catarina Bravo ◽  
Alexandra M. M. Antunes ◽  
Vânia André

We report herein three novel complexes whose design was based on the approach that consists of combining commercially available antibiotics with metals to attain different physicochemical properties and promote antimicrobial activity. Thus, new isostructural three-dimensional (3D) hydrogen bonding frameworks of pipemidic acid with manganese (II), zinc (II) and calcium (II) have been synthesised by mechanochemistry and are stable under shelf conditions. Notably, the antimicrobial activity of the compounds is maintained or even increased; in particular, the activity of the complexes is augmented against Escherichia coli, a representative of Gram-negative bacteria that have emerged as a major concern in drug resistance. Moreover, the synthesised compounds display similar general toxicity (Artemia salina model) levels to the original antibiotic, pipemidic acid. The increased antibacterial activity of the synthesised compounds, together with their appropriate toxicity levels, are promising outcomes.


1970 ◽  
Vol 7 (1) ◽  
pp. 23-26 ◽  
Author(s):  
Mohammad S Rahman ◽  
Mohammed Z Rahman ◽  
Md Abdul Wahab ◽  
Rasheduzzaman Chowdhury ◽  
Mohammad A Rashid

The antimicrobial activity of methanol extracts of 17 plant species of Bangladesh was evaluated by the agar disc diffusion method. Among those, eight plant extracts exhibited potent antimicrobial activity against a wide variety of Gram positive and Gram negative bacteria and fungi at a concentration of 400 μg /disc.Key words: Antimicrobial activity, Disc diffusion method.DOI = 10.3329/dujps.v7i1.1213Dhaka Univ. J. Pharm. Sci. 7(1): 23-26, 2008 (June)


Author(s):  
Sreedevi MEESRAGANDA ◽  
Raghavendra Gum Prasad ALURU ◽  
Spoorthy Yadan NARASIMBA ◽  
Ravindnmath Laxmana Rao Krishna RAO

A series of novel substituted l-[5-(2-methyl-5-nitro-4phenyl-imidazol-lyl methyl)-2-phenyl-(1,3,4)oxadiazol-3-yl]-ethanones have been synthesized. Formation of 1,3,4-oxadiazole ring was accomplished by the reaction of the corresponding hydrazide with acetic anhydride. The structure determination of these compounds has been made on the basis of IR, 1H NMR, and elemental analysis. All the compounds were screened for their antibacterial activity. The antimicrobial activity of title compounds were examined against two gram-negative (Staphylococcus aureus and Bacillus subtilis), two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and antifungal activity was carried out against Candida albicans. The MIC values for the newly synthesized compounds have been assessed by serial dilution method All the compounds demonstrated potent antibacterial activity.


Author(s):  
Sushma Vashisht ◽  
Manish Pal Singh ◽  
Viney Chawla

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.


Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tessa B. Moyer ◽  
Ashleigh L. Purvis ◽  
Andrew J. Wommack ◽  
Leslie M. Hicks

Abstract Background Plant defensins are a broadly distributed family of antimicrobial peptides which have been primarily studied for agriculturally relevant antifungal activity. Recent studies have probed defensins against Gram-negative bacteria revealing evidence for multiple mechanisms of action including membrane lysis and ribosomal inhibition. Herein, a truncated synthetic analog containing the γ-core motif of Amaranthus tricolor DEF2 (Atr-DEF2) reveals Gram-negative antibacterial activity and its mechanism of action is probed via proteomics, outer membrane permeability studies, and iron reduction/chelation assays. Results Atr-DEF2(G39-C54) demonstrated activity against two Gram-negative human bacterial pathogens, Escherichia coli and Klebsiella pneumoniae. Quantitative proteomics revealed changes in the E. coli proteome in response to treatment of sub-lethal concentrations of the truncated defensin, including bacterial outer membrane (OM) and iron acquisition/processing related proteins. Modification of OM charge is a common response of Gram-negative bacteria to membrane lytic antimicrobial peptides (AMPs) to reduce electrostatic interactions, and this mechanism of action was confirmed for Atr-DEF2(G39-C54) via an N-phenylnaphthalen-1-amine uptake assay. Additionally, in vitro assays confirmed the capacity of Atr-DEF2(G39-C54) to reduce Fe3+ and chelate Fe2+ at cell culture relevant concentrations, thus limiting the availability of essential enzymatic cofactors. Conclusions This study highlights the utility of plant defensin γ-core motif synthetic analogs for characterization of novel defensin activity. Proteomic changes in E. coli after treatment with Atr-DEF2(G39-C54) supported the hypothesis that membrane lysis is an important component of γ-core motif mediated antibacterial activity but also emphasized that other properties, such as metal sequestration, may contribute to a multifaceted mechanism of action.


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.


2018 ◽  
Vol 7 (2) ◽  
pp. 116-120
Author(s):  
Senthamizh Selvan N ◽  
◽  
Isaiah S ◽  

The present study was focused to examine the presence of phytoconstituents in the ethanolic extract of Shuteria involucrata plant using GC-MS analysis and Antibacterial activity. The GC-MS analysis of S. involucrata leaf was performed using Agilent 6890-JEOL GC-Mate-II Mass Spectrometer. The result of the study showed the presence of six bioactive compounds in the ethanolic extract. The antimicrobial activity was carried out by disc diffusion technique against the four selected pathogens. Among the four, tested for Antibacterial Activity Staphylococcus aureus, and Pseudomonas aeruginosa and were more susceptible to the extract, whereas the others are less susceptible. Ethanol and methanol extracts of plant materials exhibited good antibacterial activity against gram positive, gram negative bacterias


2021 ◽  
Vol 21 (5) ◽  
pp. 2879-2891
Author(s):  
Enrico Podda ◽  
M. Carla Aragoni ◽  
Massimiliano Arca ◽  
Giulia Atzeni ◽  
Simon J. Coles ◽  
...  

The reactivity of thiomorpholinium P-(4-methoxyphenyl)-N-thiomorpholin-amidodithiophosphonate (S-MorH+2)(S-Mor-adtp−) and morpholinium P-(4-methoxyphenyl)-N-morpholin-amidodithiophosphonate (O-MorH+2)(O-Mor-adtp−) towards nickel (II) dichloride hexahydrated is presented and the hydrolysis of the relevant metal complexes investigated. The hydrolytic products (S-MorH+2)2 [Ni(dtp)2]2− and (O-MorH+2)2[Ni(dtp)2]2− were characterized by means of FT-IR, 1H, and 31P NMR and XRD and the experimented P–N cleavage investigated and elucidated by means of DFT calculations. The antimicrobial activity of the neutral nickel complex [Ni(S-Mor-adtp)2] was tested against a set of Gram-positive and Gram-negative bacteria alongside with its nanodispersion in a silica matrix. The complex [Ni(S-Mor-adtp)2] did not show antibacterial activity, whilst the nano-dispersed sample [Ni(S-Mor-adtp)2]_SiO2 demonstrated inhibition to growth of Staphylococcus aureus. The nanocomposites were fully characterized by means of XRPD, TGA, SEM and dinitrogen sorption techniques.


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