Preparation and Characterization of Polyaniline and Ag/ Polyaniline Composite Nanoporous Particles and Their Antimicrobial Activities

2017 ◽  
Vol 26 (2) ◽  
pp. 434-442 ◽  
Author(s):  
Mohamed Shaban ◽  
Mohamed Rabia ◽  
Walid Fathallah ◽  
Neama Abd El-Mawgoud ◽  
Asmaa Mahmoud ◽  
...  
Author(s):  
SURENDRA BABU LAGU ◽  
RAJENDRA PRASAD YEJELLA

Objective: Investigation, the series of newer 2‐amino-pyridine‐3‐carbonitrile and 2‐amino-4H-pyran‐3‐carbonitrile derivative were synthesized and evaluated antimicrobial activities and antioxidant activity. Methods: Novel synthesized chalcones were further condensation to give 2-amino-3-cyanopyridine and 2-amino-3-cyanopyrans in the presence of malononitrile, pyridine, and ammonia acetate. The product is characterized by conventional and instrumental methods. Pyridine and 4-H-Pyran and their analogs occupy prime position due to their diverse applications. Results: The compounds A3C and B3C exhibited marked zone of inhibition with 30.02±0.02 mm and 29.06±0.01 mm, respectively. Docking studies suggested possible interactions with dihydrofolic reductase 4 with 9.15 and −9.67 kcal/mol, respectively. The IC50 30.28±0.01 exhibited A3C by 2,2-diphenylpicrylhydrazyl methods which is better among the series. The 2-amino-3-cyanopyridine derivatives were found good activity than 2-amino-3-cyanopyrane derivative. Among all synthesized compounds few having potent activity and some are near to the standard. Conclusion: Antimicrobial activity and antioxidant of the newly synthesized pyrans and pyridines derivatives will definitely inspire future researchers for the preparation of new analogs.


2019 ◽  
Vol 24 (2) ◽  
pp. 7-16
Author(s):  
Nabin Rana ◽  
Saraswoti Khadka ◽  
Bishnu Prasad Marasini ◽  
Bishnu Joshi ◽  
Pramod Poudel ◽  
...  

 Realizing myxobacteria as a potential source of antimicrobial metabolites, we pursued research to isolate myxobacteria showing antimicrobial properties. We have successfully isolated three strains (NR-1, NR-2, NR-3) using the Escherichia coli baiting technique. These isolates showed typical myxobacterial growth characteristics. Phylogenetic analysis showed that all the strains (NR-1, NR-2, NR-3) belong to the family Archangiaceae, suborder Cystobacterineae, and order Myxococcales. Furthermore, 16S rRNA gene sequence similarity searched through BLAST revealed that strain NR-1 showed the closest similarity (91.8 %) to the type strain Vitiosangium cumulatum (NR-156939), NR-2 showed (98.8 %) to the type of Cystobacter badius (NR-043940), and NR-3 showed the closest similarity (83.5 %) to the type of strain Cystobacter fuscus (KP-306730). All isolates showed better growth in 0.5-1 % NaCl and pH around 7.0, whereas no growth was observed at pH 9.0 and below 5.0. All strains showed better growth at 32° C and hydrolyzed starch, whereas casein was efficiently hydrolyzed by NR-1 and NR-2. Besides, preliminary antimicrobial tests from crude extracts showed activities against Gram-positive, Gram-negative bacteria, and fungi. Our findings suggest that the arcane soil habitats of Nepal harbor myxobacteria with the capability to produce diverse antimicrobial activities that may be explored to overcome the rapidly rising global concern about antibiotic resistance.


2020 ◽  
Vol 8 (7) ◽  
pp. 1083 ◽  
Author(s):  
Halil İbrahim Kaya ◽  
Ömer Şimşek

Tarhana is a traditional cereal product fermented by lactic acid bacteria (LAB) and yeast strains that has gained special interest recently as an infant nutrition. Tarhana contains wheat flour, yogurt, and various vegetables that might create a microbiological toxicological risk, especially for Bacillus cereus and Staphylococcus aureus. In this study, characterization of the metabolites responsible for antibacterial activity of Pediococcus acidilactici PFC69 and Lactococcus lactis PFC77 strains obtained from tarhana was performed, and antibacterial effects were detected against B. cereus ATCC 11778 and S. aureus ATCC 29213 during the fermentation. A total of 12,800 AU/mL antibacterial activity was observed for the supernatants of the PFC69 and PFC77 strains that were found to be stable at high temperature and in low pH conditions and sensitive to proteases, suggesting the antimicrobial metabolite is a bacteriocin. These bacteriocins were further purified and their molecular sizes were determined as 4.5 and 3.5 kDa, respectively. Importantly, inoculation of PFC69 and PFC77 to tarhana dough significantly decreased B. cereus ATCC 11778 and S. aureus ATCC 29213 amounts from the fifth day of fermentation compared to the control dough samples. P. acidilactici PFC69 and L. lactis PFC77 strains were concluded as bioprotective cultures for tarhana and these strains were offered for other cereal-based fermentations.


2009 ◽  
Vol 2 (1) ◽  
pp. 178-185
Author(s):  
M. Akhand ◽  
M. A. A. Al-Bari ◽  
M. A. Islam ◽  
Proma Khondkar

A new actinomycete strain was isolated from Western part of Bangladesh and identified as a new Streptomyces species on the basis of its morphological, biochemical, cultural characteristics and 16S rRNA data. The present paper describes the isolation and characterization of compound 1 from this new Streptomyces species with the help of various chemical and spectroscopic methods. Antimicrobial activity of compound 1 was tested by disc diffusion assay method and compared with that of standard antibiotics (Kanamycin for antibacterial activity and Nystatin for antifungal activity). The compound has been found to exhibit moderate to strong antimicrobial activity against the test organisms. Cytotoxicity of the compound 1 and the pet. ether extract of Czapek Dox (alkaline) broth of Streptomyces species was evaluated in brine shrimp bioassay with LC50 values of 23.85 µg/ml (ppm) and 19.95 µg/ml (ppm), respectively. Keywords: Streptomyces; Antimicrobial activity; Cytotoxicity. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.3079                  J. Sci. Res. 2 (1), 178-185 (2010)  


2020 ◽  
Vol 16 (1) ◽  
pp. 39-48
Author(s):  
O.A. Adetunji ◽  
B. Adesanwo ◽  
O.A. Odeniyi

Background: Oil derived from Cocos nucifera Linne (CNL) has been used in formulating creams; however, its use in formulation of microemulsion is not well documented in literature.Objective: Oils obtained from CNL were characterized, used in the formulation of microemulsions and were evaluated for their antimicrobial properties in comparison with Castor oil BP (CO) and commercially available coconut oil (CACO).Methodology: Oil from CNL was extracted by maceration in hot – water and petroleum ether to yield naturally extracted oil (NEO) and chemically extracted oil (CEO) respectively. The NEO and CEO were used in formulating microemulsions containing pre-determined ratios (3:7, 1:1, 9:1) of oil to surfactant mix (Smix) [containing polyethylene glycol: Tween 80® at ratio 2:1] Characterization of NEO, CEO and microemulsions were carried out using elemental constituents, rheology, physico-and phyto-chemical analysis, thermal stability and antimicrobial profiles as parameters. Statistical analysis was done using ANOVA at p<0.05Results: The NEO and CEO contained antraquinones and terpenoids, but were devoid of lead, copper, zinc, alkaloids, saponins, cardiac glycosides and flavonoids. Viscosity profiles were in the order CO>CEO>CACO>NEO. The microemulsions were in the size range 54.24±0.26-89.08±0.07 μm. Microemulsions of oil:Smix (3:7) were the most stable. Inhibition ranking was Candida sp.D25 (CEO:Smix>CACO: Smix>NEO: Smix>NEO>CO>CEO), Candida sp.D33 (CEO = CO>CACO: Smix=NEO>CEO:Smix=NEO:Smix), Staphylococcus sp.DS2 (NEO>CO>CACO:Smix>NEO: Smix>CEO: Smix=CEO) and Pseudomonas sp.DP8 (NEO:Smix>CO>CACO:Smix>CEO:Smix=NEO > CEO).Conclusion: Oil derived from CNL has good potentials as an excipient in the formulation of microemulsions and the method of oil extraction had a significant effect on the antimicrobial activities and on the microemulsions formulated using the oils. Keywords: Coconut oil, extraction method, castor oil, microemulsions, antimicrobial properties.


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