• Bulletin of the Korean Chemical Society
• /
• 제31권12호
• /
• pp.3605-3610
• /
• 2010

In the present study, some quinoline derivatives have been synthesized like 8-methoxy-4-methyl-2-amino-(3'-chloro-2'-oxo-4'-substituted aryl-1'-azetidinyl)quinolines 8-12 and 8-methoxy-4-methyl-2-amino-(2'-substituted aryl-4'-oxo-1',3'-thiazolidin-3'-yl) quinolines 13-17 from 8-methoxy-4-methyl-2-(substituted arylidenyliminoamino)-quinolines 3-7. The structural assignments of these compounds were based on spectral (IR, $^1H$-NMR, Mass) and elemental (C, H, N) analysis. Further, these compounds were evaluated for antibacterial activity against various bacterial strains. Three compounds 10, 11 and 16 were found to exhibit potent antibacterial activity as compared to the standard drug amphicillin.

• 대한한방내과학회지
• /
• 제24권2호
• /
• pp.269-282
• /
• 2003

Water and ethanol extracts of 67 species of medicinal plants were tested to determine antimicrobial activity against Helicobacter pylori. Among them, the extracts of Coptis japonica showed the best antibacterial activity. The extract of C. japonica showed four major spots on TLC plate and the Rf values of the spots were 0.07, 0.13, 0.21 and 0.73, respectively. Except for the spot of Rf 0.73, other three spots inhibited the cell growth of H. pylori. As shown in HPLC analysis, three antimicrobial spots contain berberine, major antimicrobial substance of C. japonica. However, the spot of Rf 0.13 had higher activity than berberine. The concentrated water extract of three prescribed medicines related with C. japonica showed good antibacterial activity against H. pylori.

• 한국축산식품학회지
• /
• 제21권1호
• /
• pp.64-70
• /
• 2001

The extraction procedure and HPLC condition were modified to analyze the residues of oxytetracycline, sulfamethoxazole and chloramphenicol in pork, simultaneously. The antibacterial agents in pork were extracted with 0.02M EDTA-Mcilivine buffer:ethanol:acetonitrile (5:3:2). After the removal of fat with n-hexane, the extracts were evaporated and purified with Sep-pak $C_{18}$ cartridge column using 0.01M oxalic acid 0.1% (v/v) triethylamine (TEA) in acetonitrile. The peak of antibacterial agents was detected with $\mu$ Bondapak C18 column, UV detector (280nm) and 0.01M oxalic acid: methanol: acetonitrile (7.5:2.0:0.5). Detection limits for three antibacterial standards were 0.03 ppm. Calibration curves were linear between 0.03 and 2.0 ppm (R$^2$>0.999). When spiked the level of 1.0 ppm of oxytetracycline, sulfamethoxazole and chloramphenicol into meats, the recoveries from meats were 77.3%, 79.7% and 59.3%, respectively. These results showed that the modified extraction method provided good analytical resolution and the recoveries of the above antibacterial agents in meats.

• Environmental Engineering Research
• /
• 제11권6호
• /
• pp.325-332
• /
• 2006

A novel series of polystyrene (PS) beads containing various sulfonamide groups was prepared, and their chemical stabilities in an aqueous solution were tested in order to determine their ability to inactivate microbes. By reacting aminomethyl polystyrene (AM PS) beads or carboxy polystyrene beads with various benzenesulfonic acid derivatives, the sulfonamide groups were introduced on the PS beads. The characteristics of the product beads were analyzed by elementary analysis after the substitution of various sulfonamide groups. Energy Dispersive Spectroscopy (EDS), and FT-IR analysis were used to analyze the elemental functional group composition, respectively. The hydrolytic stabilities of the PS beads containing various sulfonamide groups along with the relationship between the swelling ratio and their hydrophilicity were investigated. The antibacterial activity of the beads was determined by their ability to inactivate E. coli. This study reports that PS beads containing sulfonamide groups had lasting antibacterial efficacy over a satisfactory period, whilst maintaining their chemical stabilities against hydrolysis. The 8 synthesized polymer beads exhibited antibacterial ability.

• 한국재료학회지
• /
• 제30권5호
• /
• pp.252-261
• /
• 2020

We prepare ZnO nanoparticles by environmentally friendly synthesis using Cyathea nilgiriensis leaf extract. Various phytochemical constituents are identified through the assessment of ethanolic extract of plant Cyathea nilgiriensis holttum by GC-MS analysis. The formation of ZnO nanoparticles is confirmed by FT-IR, XRD, SEM-EDX, TEM, SAED and PSA analysis. TEM observation reveals that the biosynthesized ZnO nanopowder has a hexagonal structure. The calculated average crystallite size from the high intense plane of (1 0 1) is 29.11 nm. The particle size, determined by TEM analysis, is in good agreement with that obtained by XRD analysis. We confirm the formation of biomolecules in plant extract by FT-IR analysis and propose a possible formation mechanism of ZnO nanoparticles. Disc diffusion method is used for the analyses of antimicrobial activity of ZnO nanoparticles. The synthesized ZnO nanoparticles exhibit antimicrobial effect in disc diffusion experiments. The biosynthesized ZnO nanoparticles display good antibacterial performance against B. subtilis (Gram-positive bacteria) and K. pneumonia (Gram-negative bacteria). Bio-synthesized nanoparticles using green method are found to possess good antimicrobial performance.

• Preventive Nutrition and Food Science
• /
• 제14권2호
• /
• pp.162-167
• /
• 2009

Various fermented foods were screened in search of food-grade bacteria that produce bacteriocins active against Gram-negative pathogens. An isolate from a mold-ripened cheese presented antibacterial activity against Gram-positive and Gram-negative bacteria. The most active isolate was identified as Lactobacillus casei by a biochemical method, ribotyping, and membrane lipid analysis, and was designated as OSY-LB6A. The cell extracts of the isolate showed inhibition against Escherichia coli p220, E. coli O157, Salmonella enerica serovar Enteritidis, Salmonella Typhimurium, and Listeria monocytogenes. The antibacterial nature of the cell extract from the isolate was confirmed by eliminating the inhibitory effects of acid, hydrogen peroxide, and lytic bacteriophages. The culture supernatant and cell extract retained antibacterial activity after heating at $60{\sim}100^{\circ}C$ for $10{\sim}20$ min. The activity of the cell extract from Lb. casei was eliminated by pronase and lipase. Finally, the cell extract showed a bactericidal mode of action against E. coli in phosphate buffer solution, but it was bacteriostatic in broth medium and food extracts.

• Elastomers and Composites
• /
• 제52권3호
• /
• pp.201-210
• /
• 2017

We studied the antibacterial effect and mechanical properties of PLA composites with in organic porous zeolite-type bacteriocides. The specimens were prepared by an intermeshing co-rotating twin screw extruder using different contents of inorganic bacteriocide. The degree of dispersion of the in organic bacteriocide in the PLA composite was confirmed by FE-SEM. The contents of Ag and Zn in the composite were also investigated by energy dispersive spectroscopy at different concentrations of the inorganic bacteriocide. The antibacterial effects were analyzed by turbidity analysis, shaking culture, and drop-test. The mechanical properties, such as the tensile and flexural properties, impact strength, and physical properties, were also investigated. As the content of inorganic bacteriocide increased, the antibacterial activity was increased, especially against Staphylococcus aureus. Mechanical properties, namely, tensile strength, elongation, flexural strength, and impact strength, tended to decrease with an increase in inorganic bacteriocide content, but the tensile and flexural modulus increased.

• Journal of Microbiology and Biotechnology
• /
• 제15권5호
• /
• pp.1039-1046
• /
• 2005

The salt resistance of antibacterial activity and synergistic effect with clinically used antibiotic agents are critical factors in developing effective peptide antibiotic drugs. For this reason, we investigated the resistance of antibacterial activity to antagonism induced by NaCl and $MgCl_2$ and the synergistic effect of P20 with cefotaxime. P20 is a 20-residue synthetic peptide derived from a cecropin A (CA)-melittin(ME) hybrid peptide. In this study, P20 was found to have potent antibacterial activity against clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) strains without hemolytic activity against human erythrocytes. The combination study revealed that P20 in combination with cefotaxime showed synergistic antibacterial activity in an energy-dependent manner. We also confirmed the synergism between P20 and cefotaxime by fluorescence-activated flow cytometric analysis by staining bacterial cells with propidium iodide (PI) and bis-(1,3-dibutylbarbituric acid) trimethine oxonol (BOX). This study suggests that P20 may be useful as a therapeutic antibiotic peptide with synergistic effect in combination with conventional antibiotic agents.

• 셀메드
• /
• 제2권4호
• /
• pp.37.1-37.4
• /
• 2012

In the present study, the volatile oil, chloroform extract and methanol extract of the woods of the plants Cedrus deodara and Pinus roxburghii were screened for their antibacterial and antifungal activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Streptococcus pyogenes, Candida albicans, Aspergillus niger, and Aspergillus clavatus using the Agar diffusion method. The susceptibilities of the microorganisms to the extracts were compared with each other and with a selected standard antibiotic. It was observed that the volatile oil and chloroform extracts showed the significant antibacterial activities while the least antibacterial activity was recorded with the methanolic extracts. The higher Minimum Inhibitory Concentration value of the extracts and oils against fungus suggested that the plants may possess less antifungal activity. Phytochemical analysis and thin-layer chromatography profiling revealed the presence of flavonoids and terpenoids in the oil and chloroform extracts, which could explain the antimicrobial activity. The findings suggest that the Cedrus deodara and Pinus roxburghii have antimicrobial properties and they can be used in the treatment of infectious diseases. However, further work is required in order to isolate the active constituents of the plants responsible for the antibacterial activity.

• 한국재료학회지
• /
• 제16권10호
• /
• pp.639-646
• /
• 2006

Over the last two decades, microbiologically influenced corrosion (MIC) of metallic materials has received considerable attention due to its serious effects on industrial field. In this context, it is important to devise control methods which inhibit biofilm formation on various metallic compounds and are compatible with environment. It was change of various conditions (duty cycle, current density, $AgNO_3$ concentration and pH) for injection of Ag particles in anodized Aluminum alloy pore using pulsed current. Optimal condition was obtained by means of FE-SEM, ICP analysis etc. The antibacterial metal's specimen were manufactured under optimal condition and this specimen were tested the antibacterial characterization and anticorrosion characterization. In result of test, we can confirmed that the antibacterial characterization and anticorrosion characterization of the specimens of injected Ag particles in anodized Aluminum alloy pore using pulsed current were better than the anodized Aluminum alloy specimens.