scholarly journals Poly(3-hydroxybutyrate) Modified by Nanocellulose and Plasma Treatment for Packaging Applications

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1249 ◽  
Author(s):  
Denis Mihaela Panaitescu ◽  
Eusebiu Rosini Ionita ◽  
Cristian-Andi Nicolae ◽  
Augusta Raluca Gabor ◽  
Maria Daniela Ionita ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Plasma Treatment ◽  
Food Packaging ◽  
Cellulose Nanofibers ◽  
Plasma Coating ◽  
Melting Behavior ◽  
Zno Nanoparticle ◽  
Melt Compounding ◽  
Green Solution

In this work, a new eco-friendly method for the treatment of poly(3-hydroxybutyrate) (PHB) as a candidate for food packaging applications is proposed. Poly(3-hydroxybutyrate) was modified by bacterial cellulose nanofibers (BC) using a melt compounding technique and by plasma treatment or zinc oxide (ZnO) nanoparticle plasma coating for better properties and antibacterial activity. Plasma treatment preserved the thermal stability, crystallinity and melting behavior of PHB‒BC nanocomposites, regardless of the amount of BC nanofibers. However, a remarkable increase of stiffness and strength and an increase of the antibacterial activity were noted. After the plasma treatment, the storage modulus of PHB having 2 wt % BC increases by 19% at room temperature and by 43% at 100 °C. The tensile strength increases as well by 21%. In addition, plasma treatment also inhibits the growth of Staphylococcus aureus and Escherichia coli by 44% and 63%, respectively. The ZnO plasma coating led to important changes in the thermal and mechanical behavior of PHB‒BC nanocomposite as well as in the surface structure and morphology. Strong chemical bonding of the metal nanoparticles on PHB surface following ZnO plasma coating was highlighted by infrared spectroscopy. Moreover, the presence of a continuous layer of self-aggregated ZnO nanoparticles was demonstrated by scanning electron microscopy, ZnO plasma treatment completely inhibiting growth of Staphylococcus aureus. A plasma-treated PHB‒BC nanocomposite is proposed as a green solution for the food packaging industry.

Antibacterial Activity of Desert Truffles from Saudi Arabia Against Staphylococcus aureus and Pseudomonas aeruginosa

2017 ◽  
Vol 19 (2) ◽  
pp. 121-125 ◽  
Author(s):  
Domenico Schillaci ◽  
Maria Grazia Cusimano ◽  
Stella Maria Cascioferro ◽  
Vita Di Stefano ◽  
Vincenzo Arizza ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Saudi Arabia ◽  
Desert Truffles

Antibacterial Activity of Thujaoccidentalis,ThujaorientalisandChamaecyparisobtusa

2017 ◽  
Vol 8 (03) ◽  
Author(s):  
Kyoung- Sun Seo ◽  
Seong Woo Jin ◽  
Seongkyu Choi ◽  
Kyeong Won Yun
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibacterial Agent ◽  
Methanol Extract ◽  
The Other ◽  
Diffusion Method ◽  
E Coli ◽  
Agar Diffusion ◽  
Agar Diffusion Method ◽  
Crude Methanol Extract

The antibacterial activity of three Cupressaceae plants (Thujaoccidentalis,ThujaorientalisandChamaecyparisobtusa) was tested against three bacteria using the agar diffusion method. The ether and ethylacetate fraction of crude methanol extract from the three plants showed potent antibacterial activity against the tested microorganisms. The result showed that Staphylococcus aureus revealed the most sensitivity among the tested bacteria. Thujaoccidentalisether fraction and Thujaorientalis hexane fraction exhibited the highest antibacterial activity against Staphylococcus aureus. E. coli was shown the highest MIC values compared to the other two tested bacteria, which indicates the lowest antibacterial activity against the bacterium. This study promises an interesting future for designing a potentially active antibacterial agent from the three Cupressaceae plants.

Chemical Composition and Antibacterial Activity of Essential Oils of Three Medicinal Plants from Algerian Semi-Arid Climatic Zone

2018 ◽  
Vol 16 (S1) ◽  
pp. S155-S163 ◽  
Author(s):  
S. Mehalaine ◽  
O. Belfadel ◽  
T. Menasria ◽  
A. Messaili
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Essential Oils ◽  
Rosmarinus Officinalis ◽  
Salvia Officinalis ◽  
Thymus Algeriensis

The present study was carried out to determine, for the first time, the chemical composition and antibacterial activity of essential oils derived from the aerial parts of three aromatic plants Thymus algeriensis Boiss & Reut, Rosmarinus officinalis L., and Salvia officinalis L. growing under semiarid conditions. The essential oils were chemically analyzed and identified by gas chromatography (GC) and GC/ mass spectrometry (GC/MS) and their antimicrobial activity was individually evaluated against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa using both agar disk diffusion and agar dilution methods. The major constituents of Thymus algeriensis essential oil were identified as camphor (13.62%), 1,8-cineol (6.00%), borneol (5.74%), viridiflorol (4.00%), and linalool (3.93%). For Rosmarinus officinalis essential oil, 48 compounds were characterized, of which the main constituents were camphor (17.09%), Z-β-ocimene (10.88%), isoborneol (9.68%), α-bisabolol (7.89%), and borneol (5.11%). While, Salvia officinalis essential oil was characterized by β-thujone (16.44%), followed by viridiflorol (10.93%), camphor (8.99%), 1,8-cineol (8.11%), trans-caryophyllene (5.85%), and α-humulene (4.69%) as the major components. Notably, results from antibacterial screening indicated that Thymus algeriensis and Salvia officinalis essential oils exhibited a strong inhibitory effect against both Escherichia coli and Staphylococcus aureus compared to Rosmarinus officinalis essential oil. Further, less activity was recorded against Pseudomonas aeruginosa for the three tested essential oils.

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 of Chalcones and Nucleosides Incorporating [1, 3, 4]Oxadiazolenone Core and Evaluation of their Antifungal and Antibacterial Activities

2020 ◽  
Vol 15 (6) ◽  
pp. 665-679
Author(s):  
Alok K. Srivastava ◽  
Lokesh K. Pandey
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Antifungal Activity ◽  
Aspergillus Niger ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Good Antibacterial Activity

Background: [1, 3, 4]oxadiazolenone core containing chalcones and nucleosides were synthesized by Claisen-Schmidt condensation of a variety of benzaldehyde derivatives, obtained from oxidation of substituted 5-(3/6 substituted-4-Methylphenyl)-1, 3, 4-oxadiazole-2(3H)-one and various substituted acetophenone. The resultant chalcones were coupled with penta-O-acetylglucopyranose followed by deacetylation to get [1, 3, 4] oxadiazolenone core containing chalcones and nucleosides. Various analytical techniques viz IR, NMR, LC-MS and elemental analysis were used to confirm the structure of the synthesised compounds.The compounds were targeted against Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and Aspergillus flavus, Aspergillus niger and Fusarium oxysporum for antifungal activity. Methods: A mixture of Acid hydrazides (3.0 mmol) and N, Nʹ- carbonyl diimidazole (3.3 mmol) in 15 mL of dioxane was refluxed to afford substituted [1, 3, 4]-oxadiazole-2(3H)-one. The resulted [1, 3, 4]- oxadiazole-2(3H)-one (1.42 mmol) was oxidized with Chromyl chloride (1.5 mL) in 20 mL of carbon tetra chloride and condensed with acetophenones (1.42 mmol) to get chalcones 4. The equimolar ratio of obtained chalcones 4 and β -D-1,2,3,4,6- penta-O-acetylglucopyranose in presence of iodine was refluxed to get nucleosides 5. The [1, 3, 4] oxadiazolenone core containing chalcones 4 and nucleosides 5 were tested to determined minimum inhibitory concentration (MIC) value with the experimental procedure of Benson using disc-diffusion method. All compounds were tested at concentration of 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, 0.62 mg/mL, 0.31 mg/mL and 0.15 mg/mL for antifungal activity against three strains of pathogenic fungi Aspergillus flavus (A. flavus), Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum) and for antibacterial activity against Gram-negative bacterium: Escherichia coli (E. coli), and two Gram-positive bacteria: Staphylococcus aureus (S. aureus) and Bacillus subtilis(B. subtilis). Result: The chalcones 4 and nucleosides 5 were screened for antibacterial activity against E. coli, S. aureus and B. subtilis whereas antifungal activity against A. flavus, A. niger and F. oxysporum. Compounds 4a-t showed good antibacterial activity whereas compounds 5a-t containing glucose moiety showed better activity against fungi. The glucose moiety of compounds 5 helps to enter into the cell wall of fungi and control the cell growth. Conclusion: Chalcones 4 and nucleosides 5 incorporating [1, 3, 4] oxadiazolenone core were synthesized and characterized by various spectral techniques and elemental analysis. These compounds were evaluated for their antifungal activity against three fungi; viz. A. flavus, A. niger and F. oxysporum. In addition to this, synthesized compounds were evaluated for their antibacterial activity against gram negative bacteria E. Coli and gram positive bacteria S. aureus, B. subtilis. Compounds 4a-t showed good antibacterial activity whereas 5a-t showed better activity against fungi.

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