scholarly journals Synthesis, Characterization, and Antimicrobial Evaluation of Random Poly(ester-Carbonate)s Bearing Pendant Primary Amine in the Main Chain

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2640
Author(s):  
Peng Dong ◽  
Jing Feng ◽  
Sujuan Li ◽  
Tingli Sun ◽  
Qingshan Shi ◽  
...  
Keyword(s):  
Primary Amine ◽  
Ring Opening ◽  
Inhibitory Concentration ◽  
Cyclic Carbonate ◽  
Random Copolymers ◽  
Feed Ratio ◽  
E Coli ◽  
Antimicrobial Evaluation ◽  
Low Cytotoxicity ◽  
Poly Caprolactone

Starting from primary amine bearing cyclic carbonate tert-butyl-(2-oxo-1,3-dioxan-5-yl) carbamate (TBODC) and caprolactone (CL), amphiphilic poly(caprolactone-ran-amino trimethyl carbonate)s (P(CL-ran-ATC)s) random copolymers with controlled molecular weight and composition were synthesized via ring opening polymerization (ROP) and deprotection, using stannous octoate (Sn(Oct)2) as catalyst and benzyl alcohol (BnOH) as initiator. Therefore, hydrophilic/lipophilic ratio (HLR) of the P(CL-ran-ATC)s copolymers can be finely adjusted by the feed ratio of TBODC and CL. The antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) of P(CL-ran-ATC)s were proportional to HLR, and P(CL-ran-ATC)s presented more vigorous bactericidal activity towards S. aureus. The minimum inhibitory concentration (MIC) values of P(CL-ran-ATC 50.9%) are 2000 μg mL−1 and 3000 μg mL−1 for S. aureus and E. coli. While P(CL-ran-ATC 50.9%) exhibited deficient hemolytic activity as 1.41%. In addition, the P(CL-ran-ATC)s showed extremely low cytotoxicity towards fibroblast L929 cells.

scholarly journals Synthesis of Bi- and Trifunctional Cyclic Carbonates Based on Trimethylolpropane and Their Application to Networked Polyhydroxyurethanes

2016 ◽  
Vol 5 (3) ◽  
pp. 11 ◽  
Author(s):  
Hiroyuki Matsukizono ◽  
Takeshi Endo
Keyword(s):  
Ring Opening ◽  
Cyclic Carbonate ◽  
The Other ◽  
Hydroxyl Group ◽  
Feed Ratio ◽  
Diphenyl Carbonate ◽  
Cyclic Carbonates ◽  
Terephthaloyl Chloride ◽  
Molecular Weights ◽  
Trimesoyl Chloride

<p class="1Body">The reaction of trimethylolpropane (TMP) and diphenyl carbonate gives three types of TMP-based six-membered cyclic carbonates (TMPCs) via phosgene-free route. TMPC having one hydroxyl group (TMPC-OH) reacted with terephthaloyl chloride or trimesoyl chloride to give bifunctional (Ph-TMPC<sub>2</sub>) or trifunctional cyclic carbonate monomers (Ph-TMPC<sub>3</sub>), respectively. The ring-opening polyaddition of Ph-TMPC<sub>2</sub> and conventional diamines efficiently proceeded without the cleavage of ester bonds to afford linear polyhydroxyurethanes (PHUs) with well-controlled molecular weights and polydispersities via isocyanate-free route. Moreover, the polyaddition of Ph-TMPC<sub>2</sub> and diamine at TMPC<sub>2</sub>/diamine feed ratio of 1.1 afforded PHUs having cyclic carbonate terminals, the hydroxyl side chains of which were easily reacted with acetic anhydride to give acetylated PHUs with cyclic carbonate terminals. On the other hand, the polyaddition at Ph-TMPC<sub>2</sub>/diamine feed ratio of 0.91 gave PHUs with amine terminals. The copolymerization of Ph-TMPC<sub>2</sub>, Ph-TMPC<sub>3</sub> and diamine gives PHUs comprising covalently-bridged networked structures. After DMF solutions of Ph-TMPC<sub>2</sub>, Ph-TMPC<sub>3</sub> and diamines were simply kept at 60 °C overnight, networked PHU films with well transparency were successfully fabricated. The PHU films prepared at different diamines showed similar transparency and thermal stability, while the mechanical properties were significantly affected by the methylene spacers of diamines.</p>

In Vitro Antibacterial activity of ethanolic extract of Myrsine africana against laboratory Strains of Pathogenic Organisms

2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Ethanolic Extract ◽  
Ethanol Extract ◽  
E Coli ◽  
Zones Of Inhibition ◽  
In Vitro Antibacterial Activity ◽  
Myrsine Africana

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.

scholarly journals Transcriptome analysis of Escherichia coli K1 after therapy with hesperidin conjugated with silver nanoparticles

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abdulkader Masri ◽  
Naveed Ahmed Khan ◽  
Muhammad Zarul Hanifah Md Zoqratt ◽  
Qasim Ayub ◽  
Ayaz Anwar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Neonatal Meningitis ◽  
E Coli ◽  
Drug Candidates ◽  
Metabolic Genes ◽  
Genetic Mechanisms ◽  
Cell Stress Response

Abstract Backgrounds Escherichia coli K1 causes neonatal meningitis. Transcriptome studies are indispensable to comprehend the pathology and biology of these bacteria. Recently, we showed that nanoparticles loaded with Hesperidin are potential novel antibacterial agents against E. coli K1. Here, bacteria were treated with and without Hesperidin conjugated with silver nanoparticles, and silver alone, and 50% minimum inhibitory concentration was determined. Differential gene expression analysis using RNA-seq, was performed using Degust software and a set of genes involved in cell stress response and metabolism were selected for the study. Results 50% minimum inhibitory concentration with silver-conjugated Hesperidin was achieved with 0.5 μg/ml of Hesperidin conjugated with silver nanoparticles at 1 h. Differential genetic analysis revealed the expression of 122 genes (≥ 2-log FC, P< 0.01) in both E. coli K1 treated with Hesperidin conjugated silver nanoparticles and E. coli K1 treated with silver alone, compared to untreated E. coli K1. Of note, the expression levels of cation efflux genes (cusA and copA) and translocation of ions, across the membrane genes (rsxB) were found to increase 2.6, 3.1, and 3.3- log FC, respectively. Significant regulation was observed for metabolic genes and several genes involved in the coordination of flagella. Conclusions The antibacterial mechanism of nanoparticles maybe due to disruption of the cell membrane, oxidative stress, and metabolism in E. coli K1. Further studies will lead to a better understanding of the genetic mechanisms underlying treatment with nanoparticles and identification of much needed novel antimicrobial drug candidates.

scholarly journals Synthesis and In Vitro Antimicrobial Evaluation of Photoactive Multi—Block Chalcone Conjugate Phthalimide and 1,8-Naphthalimide Novolacs

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1859
Author(s):  
Periyan Durairaju ◽  
Chinnasamy Umarani ◽  
Govindasami Periyasami ◽  
Perumberkandigai Adikesavan Vivekanand ◽  
Mostafizur Rahaman
Keyword(s):  
Spectroscopic Analysis ◽  
Photophysical Properties ◽  
Gel Permeation Chromatography ◽  
13C Nmr Spectroscopy ◽  
Antimicrobial Activities ◽  
Microbial Activities ◽  
E Coli ◽  
Molecular Weights ◽  
Antimicrobial Evaluation

Herein we report new multiblock chalcone conjugate phthalimide and naphthalimide functionalized copolymers with a topologically novel architecture synthesis using nucleophilic substitution and polycondensation methodology. The structures of the synthesized novolacs were elucidated on the basis of their spectroscopic analysis including FTIR, 1H NMR, and 13C NMR spectroscopy. Further, the number-average and weight-average molecular weights of the novolac polymers were determined by gel permeation chromatography (GPC). We examined the solubility of the synthesized polymers in various organic solvents including CHCl3, CH3CN, THF, H2O, CH3OH, DMSO, and DMF and found they are insoluble in both methanol and water. The novolac polymers were evaluated for their photophysical properties and microbial activities. The investigation of the antimicrobial activities of these polymers reveals significant antimicrobial activity against the pathogens E. coli, S. aureus, C. albicans, and A. niger.

scholarly journals A Facile Synthesis and Studies of Some New Chalcones and Their Derivatives Based on Heterocyclic Ring

2012 ◽  
Vol 9 (4) ◽  
pp. 1897-1905 ◽  
Author(s):  
A. Solankee ◽  
K. Patel ◽  
R. Patel
Keyword(s):  
Inhibitory Concentration ◽  
Guanidine Hydrochloride ◽  
Heterocyclic Ring ◽  
Dilution Method ◽  
Facile Synthesis ◽  
Phenyl Hydrazine ◽  
Gram Negative ◽  
E Coli ◽  
Heterocyclic Aldehydes ◽  
Broth Dilution

Chalcones(6a-f)have been prepared by the condensation of ketone(5)and different aromatic and heterocyclic aldehydes. These chalcones(6a-f)on treatment with guanidine hydrochloride and phenyl hydrazine hydrochloride in presence of alkali give aminopyrimidines(7a-f)and phenylpyrazolines(8a-f)respectively. All the newly synthesized compounds have been characterized on the basis of IR,1HNMR spectral data as well as physical data. Antibacterial activity (minimum inhibitory concentration MIC) against Gram-positiveS. aureusMTCC 96 andS. pyogeneusMTCC 442 and Gram-negativeP. aeruginosaMTCC 1688 andE. coliMTCC 443 bacteria, as well as antifungal acivities (MIC) againstC. albicansMTCC 227,A. nigerMTCC 282 andA. clavatusMTCC 1323 were determined by broth dilution method.

scholarly journals A comparison of the antibacterial activity of some African black soaps and medicated soaps commonly used for the treatment of bacteria-infected wound

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Olufunmiso O. Olajuyigbe ◽  
Morenike O. Adeoye-Isijola ◽  
Otunola Adedayo
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Concentration ◽  
Waste Product ◽  
Antibacterial Activities ◽  
Traditional Use ◽  
E Coli ◽  
African Black ◽  
Soap Production ◽  
Inhibition Zones ◽  
Better Than

Background: Black soap is a medicinal product that could be harnessed for economic purpose if properly packaged, and misconception about its traditional use by herbalists is thrown overboard.Aims: To promote the relevance of these soaps for economic development, this study compared the antibacterial activity of black soaps with medicated soaps widely used against bacterial infections.Methods: The antibacterial activities of these soap samples were determined by agar diffusion and macrobroth dilution methods.Results: In this study, the statistical analysis of the inhibition zones showed that black soaps were significantly (p < 0.05) more active than medicated soaps used against the test bacterial isolates. The black soaps inhibited and killed the isolates better than the medicated soaps at the different concentrations used. The minimum inhibitory concentration for Klebsiella pneumoniae and Enterococcus faecalis ranged between 0.125 mg/mL and 2 mg/mL, Staphylococcus aureus (0.25–4) mg/mL, Escherichia coli (0.125–4) mg/mL and Pseudomonas aeruginosa (1–4) mg/mL. The result showed that K. pneumoniae and E. faecalis were the most susceptible, followed by E. faecalis > E. coli > S. aureus > P. aeruginosa.Conclusion: As a valuable medicinal output derivable from organic waste product that could be converted to wealth, African black soap production, utilisation and commercialisation have tremendous economic potentials. These soaps showed significant antibacterial activity greater than those of the medicated soaps. Hence, their use could be a better option in place of commercially available medicated and antiseptic soaps because of the degree of antibacterial activities they exhibited.

Toxicity of the First Ten MEIC Chemicals to Bacteria

1993 ◽  
Vol 21 (2) ◽  
pp. 151-155
Author(s):  
Gustaw Kerszman
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Linear Regression ◽  
Minimal Inhibitory Concentration ◽  
Blood Concentration ◽  
Inhibitory Concentration ◽  
Human Lymphocytes ◽  
Bacterial Species ◽  
E Coli ◽  
Mild Toxicity

The toxicity of the first ten MEIC chemicals to Escherichia coli and Bacillus subtilis was examined. Nine of the chemicals were toxic to the bacteria, with the minimal inhibitory concentration (MIC) ranging from 10-3 to 4.4M. The sensitivities of both organisms were similar, but the effect on E. coli was often bactericidal, while it was bacteriostatic for B. subtilis. Digoxin was not detectably toxic to either bacterial species. Amitriptyline and FeSO4 were relatively less toxic to the bacteria than to human cells. For seven chemicals, a highly significant linear regression was established between log MIC in bacteria and log of blood concentration, giving lethal and moderate/mild toxicity in humans, as well as with toxicity to human lymphocytes.

Effectiveness of ZnO Nano Particles against the Foodborne Microbial Pathogens E. coli and S. aureus

2020 ◽  
Vol 15 (2) ◽  
pp. 87-94
Keyword(s):  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Antimicrobial Effect ◽  
Nano Particles ◽  
Microbial Pathogens ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests

In this work, various concentrations of ZnO nano particles, prepared by the coprecipitation method with a size range of 47-68 nm, have been investigated as antimicrobial agents. Dilution antimicrobial susceptibility tests were carried out on two kinds of microbes (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli) according to the standard method recommended by Clinical and Laboratory Standards Institute, CLSI-2015-M07-A10. The results showed that the antimicrobial effect is larger, the higher the concentration of ZnO nano particles in solution. It was also found that Gram-positive microbes are more sensitive to ZnO nano particles when compared with the Gram-negative ones. The minimum inhibitory concentration (MIC) for E. coli was found to be 50 mg/mL while that for S. aureus was 25 mg/mL. The minimum bactericidal concentration (MBC) was 1600 mg/mL for E. coli and 800 mg/mL for S. aureus.

Preparation and disinfection properties of graphene oxide/trichloroisocyanuric acid disinfectant

2021 ◽  
Author(s):  
li li jiang ◽  
Su Xu ◽  
Haitao Yu ◽  
Qi Cui ◽  
Rui Cao
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Kinetic Curve ◽  
X Ray ◽  
Bacterial Inhibition ◽  
E Coli ◽  
Blending Method ◽  
Trichloroisocyanuric Acid

Abstract In this study, graphene oxide (GO) was first prepared by the modified Hummer method. Then, the GO/trichloroisocyanuric acid (TCCA) composite was prepared by loading TCCA into GO with the blending method. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and atomic force microscopy were used to characterize the composite. The results showed that TCCA was successfully loaded on the surface of GO or intercalated among GO layers. Next, the antibacterial performance of the composite against Escherichia coli and Staphylococcus aureus was tested by the 96-well plate assay. A bactericidal kinetic curve, bacterial inhibition tests, and the mechanism of bacterial inhibition is discussed. The results showed that the minimum inhibitory concentration of the GO/TCCA composite (GO:TCCA ratio = 1:50) was 327.5 µg/mL against E. coli and 655 µg/mL against S. aureus. At the minimum inhibitory concentration, the inhibition rate of the GO/TCCA composite exceeded 99.46% against E. coli and 99.17% against S. aureus. The bactericidal kinetic curves indicate that the GO/TCCA composite has an excellent bactericidal effect against E. coli and S. aureus.

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