scholarly journals Antimicrobial Activity of Lignin-Derived Polyurethane Coatings Prepared from Unmodified and Demethylated Lignins

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 494 ◽  
Author(s):  
Klein ◽  
Alzagameem ◽  
Rumpf ◽  
Korte ◽  
Kreyenschmidt ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Renewable Resources ◽  
Fossil Fuel ◽  
Brilliant Green ◽  
Raw Materials ◽  
Standard Test ◽  
Polyurethane Coatings ◽  
Antimicrobial Substances ◽  
Coating Color

Due to global ecological and economic challenges that have been correlated to the transition from fossil-based to renewable resources, fundamental studies are being performed worldwide to replace fossil fuel raw materials in plastic production. One aspect of current research is the development of lignin-derived polyols to substitute expensive fossil-based polyol components for polyurethane and polyester production. This article describes the synthesis of bioactive lignin-based polyurethane coatings using unmodified and demethylated Kraft lignins. Demethylation was performed to enhance the reaction selectivity toward polyurethane formation. The antimicrobial activity was tested according to a slightly modified standard test (JIS Z 2801:2010). Besides effects caused by the lignins themselves, triphenylmethane derivatives (brilliant green and crystal violet) were used as additional antimicrobial substances. Results showed increased antimicrobial capacity against Staphylococcus aureus. Furthermore, the coating color could be varied from dark brown to green and blue, respectively.

scholarly journals Chemical Composition and Preliminary Antimicrobial Activity of the Hydroxylated Sesquiterpenes in the Essential Oil from Piper barbatum Kunth Leaves

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 211 ◽  
Author(s):  
Paco Noriega ◽  
José Ballesteros ◽  
Alejandra De la Cruz ◽  
Tatiana Veloz
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Chemical Composition ◽  
Essential Oil ◽  
Forest Ecosystem ◽  
Raw Materials ◽  
The Andes ◽  
Ancestral Knowledge ◽  
Antifungal Potential

This study evaluates the antimicrobial and antifungal potential of the essential oil extracted from a species located in the Andes of Ecuador, Piper barbatum Kunth, known as “cordoncillo” or “allupa”, used by the Quichua people as an antibacterial plant for washing female genitalia in cases of infection. The most abundant molecules in the essential oil were: α- phellandrene (43.16%), limonene (7.04%); some oxygenated sesquiterpenes such as: trans-sesquisabinene hydrate (8.23%), elemol (7.21%) and others. The evaluation of antimicrobial activity showed activity in all the strains analyzed; however, those in which MIC values are considered to be very strong (less than 500 µg/mL) are: Staphylococcus aureus 264 µg/mL, Streptococcus mutans 132 µg/mL, Candida albicans 132 µg/mL and Candida tropicalis 264 µg/mL. Antimicrobial bioautography defines which molecules are responsible for the activity; thus, it was possible to establish the chromatographic regions of = 0.02 and Rf = 0.04, as those with active molecules. It was established that 4 hydroxylated sesquiterpene molecules are involved: elemol (7.21%), trans-sesquisabinene hydrate (8.23%), β–eudesmol (3.49%) and 10-epi-γ-eudesmol (1.07%); the last two being the most active. The aim of this manuscript is to analyze both the ancestral knowledge of the Quichua people of Ecuador, and the chemical-biodiversity of the Andean forest ecosystem, in order to provide new raw materials of pharmaceutical interest.

scholarly journals Bacteriocin activity of enterococci and presence of genes related to pathogenesis

2012 ◽  
Vol 30 (No. 4) ◽  
pp. 330-335 ◽  
Author(s):  
K. Trivedi ◽  
R. Sedmíková ◽  
R. Karpíšková
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Virulence Genes ◽  
Bacteriocin Production ◽  
Bacteriocin Activity ◽  
Antimicrobial Substances ◽  
Layer Technique ◽  
Genes Encoding ◽  
The Individual

In total 228 enterococci strains isolated from food were studied. Enterococcus faecalis, E. faecium, and E. casseliflavus were found to be the dominant strains while E. durans and E. mundtii were present in a smaller extent. Antimicrobial activity determined by double layer technique revealed that 150 (65.7%) strains showed antimicrobial activity against the individual tested pathogenic strains of Listeria monocytogenes, Staphylococcus aureus, and methicilin resistant S. aureus (MRSA). Cell-free neutralised supernatants (CFNS) were prepared from 150 potential bacteriocin producers. Of these 150, CFNS 107 (71.3%) strains were active in the bacteriocin production against one or more pathogenic strains tested. S. aureus and MRSA were found to be more sensitive to the antimicrobial substances than L. monocytogenes. Multiplex PCR for the detection of seven virulence genes in bacteriocin producing strains showed that 47.6% of strains were able to amplify one or more virulence genes. E. faecalis was the most virulent species. The presence of tyrdc gene was seen in all bacteriocin producing strains. None of the strains carried genes encoding the resistance to vancomycin.  

scholarly journals Synthesis of chalcone-based pyrimidine derivatives and their antimicrobial activity

2021 ◽  
Vol 57 (4) ◽  
pp. 431-437
Author(s):  
D. S. Martsinkevich ◽  
K. F. Chernyavskaya ◽  
V. A. Tarasevich
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Tropicalis ◽  
Good Activity ◽  
Pyrimidine Derivatives ◽  
Antimicrobial Substances

A series of substituted chalcones and pyrimidine derivatives on their base was synthesized. Obtained compounds were tested for antimicrobial activity and ability to increase activity of known antimicrobial substances. Pyrimidine products shown good activity against Staphylococcus aureus and Candida tropicalis. These compounds also could increase activity of modified polyguanidines against Staphylococcus aureus.

Effect of pH on the antimicrobial activity of some triphenylmethane dyes

1978 ◽  
Vol 24 (6) ◽  
pp. 658-661 ◽  
Author(s):  
W. A. Moats ◽  
S. E. Maddox Jr.
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Bacillus Cereus ◽  
Crystal Violet ◽  
Brilliant Green ◽  
Enterobacter Aerogenes ◽  
Triphenylmethane Dyes ◽  
Gram Negative ◽  
Ethyl Violet ◽  
Ph Range

Four common dyes were tested as inhibitors of four types of bacteria over the pH range 5.0–9.0. Inhibition of the gram-negative types, Salmonella anatum and Enterobacter aerogenes, was markedly affected by the pH of the medium. These organisms tolerated concentrations of crystal violet and ethyl violet about 100-fold higher at pH 5.0 than at pH 9.0. Above pH 7.0 brilliant green (BG) and malachite green (MG) were precipitated as their respective carbinols and lost their inhibitory properties with these two organisms. Two gram-positive types, Staphylococcus aureus and Bacillus cereus, were more sensitive to dyes and results were less affected by pH. The carbinol forms of MG and BG were nearly as inhibitory to these organisms as the ionized forms.

scholarly journals Antimicrobial Activity of Stenochlaena palustris and Sauropus androgynus in Staphylococcus aureus, Escherichia coli and Candidia albicans

2021 ◽  
Vol 4 (1) ◽  
pp. 32-38
Author(s):  
Lia Yulia Budiarti ◽  
Isnaini Isnaini ◽  
Puteri Dayana ◽  
Norma Sari ◽  
Nur Almira R. S.
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Single Infusion ◽  
E Coli ◽  
Antimicrobial Substances ◽  
The Difference ◽  
Combination Preparation ◽  
Young Part

Stenochlaena palustris and Sauropus androgynus are known to contains antimicrobial substances such as flavonoids, saponins and tannins compounds.The purpose of this study was to analyzes the antimicrobial activity of young and old leaf infusions of S. palustris and S. androgynus leaves against Staphylococcus aureus, Escherichia coli and Candida albicans. Analyze the antibacterial activity of a single preparations with a combination preparation of S.palustris (SP) and S.androgynus (SA) leaves infusion against S.aureus, E.coli and C.albicans. Leaves of S.palustris young part (SP1) taken 0-10 cm from shoots and old parts (SP2) 11-20 cm from shoots, while leaves of S.androgynus young part (SA1) leaves number 1 - 10 from the top and the old part (SA2) leaves number 11-20 from the top. The results showed that a single infusion of SP1 75% and SP2 75%, SA1 90% and SA2 90%, and a combination of SP1 75% and SA1 75%, SP2 75% and SA2 75% have the same activity as ampicillin in S.aureus. Single infusion of SP1 90% and SP2 90%, SA1 90% and SA2 90%, combination of SP1 75% and SA1 80% and the combination of SP2 80% and SA2 60% have the same activity as ciprofloxacin in E. coli. Single infusion of SP1 90% and SP2 90%, and a combination of SP1 80% and SA1 80%, SP2 80% and SA2 80% have the same activity as ketoconazole in C.albicans. The difference in activity due to differences in leaf parts used only occurred in E. coli, whereas in S.aureus and C.albicans (p <0.05).

scholarly journals Antimicrobial activity in cultures of endophytic fungi isolated from Talinum triangulare

2021 ◽  
Vol 43 ◽  
pp. e49786
Author(s):  
Claudio Baltazar de Sousa ◽  
Erika Alves Fonseca Amorim ◽  
Rita de Cassia Mendonça Miranda
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Endophytic Fungi ◽  
Antimicrobial Substances ◽  
Diffusion Technique ◽  
Potential Sources ◽  
Trichoderma Fungi ◽  
Potential Applications ◽  
Corynebacterium Diphtheria ◽  
Talinum Triangulare

. Endophytic fungi colonize the interior of plants without causing damage and act in symbiosis with their host. They are also potential sources of compounds with potential applications in industry, agriculture, and medicine, Thus, this study aimed to isolate and identify the endophytic fungi medicinal plant Talinum triangulare and evaluate its potential for the production of antimicrobial substances using the disk diffusion technique and testing in liquid medium front of Staphylococcus aureus ATCC SA 6538, Pseudomonas aeruginosa ATCC PA 0030, and Corynebacterium diphtheria ATCC 27012. Corynebacterium diphtheria was isolated from 3 fungi of the genus Trichoderma and Penicillium, with only the genus Trichoderma fungi showing antimicrobial activity.

scholarly journals Synthesis and antimicrobial activity of s-substituted derivatives of 1,2,4-triazol-3-thiol

2021 ◽  
pp. 64-69
Author(s):  
Yevhen Karpun ◽  
Nataliia Polishchuk
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Biological Screening ◽  
Antimicrobial Substances ◽  
Pharmaceutical Ingredients ◽  
Wide Range ◽  
Derivatives Of

The aim of the work. 1,2,4-triazole derivatives possess a wide range of pharmacological activity, so they are used for the development of drugs and active pharmaceutical ingredients. Due to the reactivity of 1,2,4-triazoles there are many options for their further structural modification on different reaction centers. Therefore, the aim of the work was to obtain new S-substituted derivatives of 1,2,4-triazole-3-thiols, study physicochemical parameters of the substances synthesized, evaluate the antimicrobial activity of new S-derivatives of the 4-R1-5-((3-(pyridin-4-yl)-1H-1,2,4-triazol-5-yl)thio)methyl)-4H-1,2,4-triazole-3-thiol series, and study some regularities of the “structure – biological activity” relationship for the synthesized compounds as well. Materials and methods. The subject of the study was new S-substituted 1,2,4-triazoles containing 2-oxopropan-1-yl and 2-aryl-2-oxoethan-1-yl substituents. The antimicrobial activity was studied by double serial dilutions on test cultures of Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), and Candida albicans (ATCC 885-653). The results of the biological screening showed that at a concentration of 125 g/mL, all synthesized substances showed activity (MIC – in the range of 31.25 - 62.5 μg/mL, MBCK - in the range of 62.5–125 μg/mL) against strains of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans. Variation of substituents on the sulfur atom did not lead to a significant change in antimicrobial and antifungal activities among derivatives of 4-R1-5-((3-(pyridin-4-yl)-1H-1,2,4-triazole-5-yl) thio)methyl)-4H-1,2,4-triazole-3-thiols. Conclusions. Biological screening data indicate the prospects for the search for new antimicrobial substances among the abovementioned derivatives of 1,2,4-triazoles. The most active compounds were 1-((4-ethyl-5-((3-(pyridin-4-yl)-1H-1,2,4-triazol-5-yl)thio)methyl)-4H-1,2,4-triazol-3-yl)thio)propan-2-one and 1-(4-methoxyphenyl)-2-(4-ethyl-5-(((3-(pyridin-4-yl)-1H)-1,2,4-triazol-5-yl)thio)methyl)-4H-1,2,4-triazol-3-yl)thio)ethanone, which showed the most pronounced antimicrobial activity against the Pseudomonas aeruginosa strain (MIC – 31.25 μg/mL, MBcK - 62.5 μg/mL)

The Study of Bacillus Subtils Antimicrobial Activity on Some of the Pathological Isolates

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Bacterial Growth ◽  
Broad Spectrum ◽  
Inhibitory Activity ◽  
Bacterial Pathogens ◽  
Inhibitory Ability ◽  
Selection Of

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.

Antimicrobial Activity of Iron-Halide Complexes Against Gram-Positive and Gram-Negative Bacteria

2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Resistance ◽  
Extracellular Dna ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Substances ◽  
Mammalian Cell Lines

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.

Sign in / Sign up

Export Citation Format

Share Document