• Title/Summary/Keyword: acidic compounds

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Identification of Potential Bacillus subtilis Probiotics from Korean Soybean Paste and Their Antimicrobial and Immune Activities

  • Seo, Weon-Taek;Nam, Sang-Hae;Lee, Chang-Kwon;Cho, Kye-Man
    • Preventive Nutrition and Food Science
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    • v.16 no.1
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    • pp.37-44
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    • 2011
  • The potential probiotic of a total of 15 Bacillus species isolated from Korean soybean paste (doenjang) was evaluated. Among those tested, the CSY191 and CSY388 strains were selected as probiotic bacteria due to their acid and bile tolerance, respectively. These strains were classified as Bacillus subtilis based on morphological, physiological, and chemotaxonomic features as well as on phylogenetic analysis based on their 16S rDNA sequences. These strains CSY191 and CSY388 showed a significant survival with rate range of 30.0 to 58.3% and of 31.0% to 58.1%, respectively, under artificial gastric acidic conditions at pH 3.0. These CSY191 and CSY388 strains appeared to have high antimicrobial activity against Salmonella Typhimurium, Bacillus cereus and Listeria monocytogenes. Also, methanol extractions (surfactin-like compounds) of strain CSY191 and strain CSY388 activated RAW264.7 microphages and induced the production of nitric oxide (NO) in a concentration-dependent manner, respectively. Therefore, strain CSY191 and strain CSY388 can be used as potential probiotics.

Biological Activities of Acidic Extracts of the Starfish Asterina pectinifera (별 불가사리(Asterina pectinifera) 조직별 초산추출물의 생리활성 탐색)

  • Go, Hye-Jin;Jo, Mi Jeong;Kim, Gun-Do;Park, Nam Gyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.2
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    • pp.122-128
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    • 2014
  • The present study was performed to examine the contraction and relaxation responses of the smooth muscles, and search for antimicrobial and antioxidant activities in the tissues, of the starfish Asterina pectinifera. Frozen samples were extracted with distilled water containing 1% acetic acid. Extracts from all tissues showed potent antimicrobial activity against Escherichia coli D31. Relatively high levels of antimicrobial activity were also detected in the body extracts. Liver, tube feet, and body extracts caused contraction responses in the dorsal retractor muscles (DRM) of the starfish. In contrast, all tissues examined exhibited contractile activity in the esophagus of squid Todarodes pacificus. In addition, liver and gonad extracts caused contraction responses upon application to the intestine of the puffer fish Takifugu pardalis. Relaxation effects on the DRM of starfish were identified in most of the extracts, while no relaxant activity was detected in body extracts. Extracts from all tissues examined also exhibited antioxidant activities. The results of this study suggest that starfish are a potential source of novel bioactive compounds.

Utilization of Waste Tires as Soil Reinforcement; (2) Environmental Effects (지반보강재로서 폐타이어의 활용; (2) 환경적 영향)

  • 윤여원;문창만;김건흥
    • Journal of the Korean Geotechnical Society
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    • v.20 no.3
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    • pp.119-128
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    • 2004
  • Environmental impact of waste tires as gound-reinforcing material is studied. Analysis for chemical compounds and toxic effect were performed on effluents from twelve lysimeters in which waste tires were mixed with sand and three initially different environmental solutions of acidic, neutral, and basic circulated through the mixture. The test results of effluents collected from the lysimeters provided that the contaminant concentrations were lower than those of Korean drinking water standards for all the selected and tested metal elements. While iron concentration increased slightly with the exposure period, other metal concentrations decreased with the number of circulation times. From the comparison with previous investigations, the contaminant concentration decreased with the increase of tire size, i.e. increases with the increase of the exposed surface of tire metals. From the toxicity tests, no deteriorative effect was observed and it could be concluded that waste tires are not biologically hostile materials.

The Influence of H+ and Cl- Ions on the Corrosion Inhibitive Effect of Poly(para-aminophenol) for Iron in Hydrochloric acid

  • Manivel, P.
    • Corrosion Science and Technology
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    • v.16 no.4
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    • pp.187-193
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    • 2017
  • Polymer amines are found to show distinct corrosion inhibition effects in acidic media. The functional groups of organic compounds have a wide role in the physical and chemical properties, for the inhibition efficiency with respect to steric factors, aromaticity, and electron density. The influence of $H^+$ ions and $Cl^-$ ions on the corrosion inhibitive effect of poly(p-aminophenol) for iron in hydrochloric acid was studied using electrochemical methods such as impedance, linear polarization, and Tafel polarization techniques. The experiments were conducted with and without the inhibitor, poly(p-aminophenol). The concentration range of $H^+$ ions and $Cl^-$ ions are from 1 M to 0.05 M and 1 M to 0.1 M, respectively. With the inhibitor poly(p-aminophenol), this study shows that inhibition efficiency decreases with the reduction of $H^+$ ion and $Cl^-$ ion concentrations in aqueous solution. Further, it reveals that the adsorption of an inhibitor on the surface of iron is dependent on the concentrations of $H^+$ and $Cl^-$ ions in the solution and the adsorption of inhibitor on the iron surface through the cationic form of amine.

Synthesis and pH-Dependent Micellization of a Novel Block Copolymer Containing s- Triazine Linkage

  • Pal Ravindra R.;Lee Doo Sung
    • Macromolecular Research
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    • v.13 no.5
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    • pp.373-384
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    • 2005
  • Novel pH-sensitive moieties containing an s-triazine ring were synthesized with sulfonamide and secondary amino groups. The synthesized pH-sensitive moieties were used for the synthesis of a pH-sensitive amphiphilic ABA triblock copolymer. The pH-sensitive triblock copolymer was composed of diblock copolymers, methoxy poly(ethylene glycol)-poly ($\varepsilon$-caprolactone-co-D,L-lactide) (MPEG-PCLA), and pH-sensitive moiety. These copolymers could be dissolved molecularly in both acidic and basic aqueous media at room temperature due to secondary amino and sulfonamide groups. The synthesized s-triazine rings containing pH-sensitive compounds were characterized by ${^1}H-NMR,\;{^13}C-NMR$, and LC/MSD spectral data. The synthesized diblock and triblock copolymers were also characterized by ${^1}H-NMR$ and GPC analyses. The critical micelle concentrations at various pH conditions were determined by fluorescence technique using pyrene as a probe. Furthermore, the micellization and demicellization study of the triblock copolymer was done with pH-sensitive groups. The sensitivity towards pH change was further established by acid-base titration.

Quality and antioxidant activity of ginseng seed processed by fermentation strains

  • Lee, Myung-Hee;Lee, Young-Chul;Kim, Sung-Soo;Hong, Hee-Do;Kim, Kyung-Tack
    • Journal of Ginseng Research
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    • v.39 no.2
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    • pp.178-182
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    • 2015
  • Background: Fermentation technology is widely used to alter the effective components of ginseng. This study was carried out to analyze the characteristics and antioxidant activity of ginseng seeds fermented by Bacillus, Lactobacillus, and Pediococcus strains. Methods: For ginseng seed fermentation, 1% of each strainwas inoculated on sterilized ginseng seeds and then incubated at $30^{\circ}C$ for 24 h in an incubator. Results: The total sugar content, acidic polysaccharides, and phenolic compounds, including p-coumaric acid, were higher in extracts of fermented ginseng seeds compared to a nonfermented control, and highest in extracts fermented with B. subtilis KFRI 1127. Fermentation led to higher antioxidant activity. The 2,2'-azine-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity was higher in ginseng seeds fermented by Bacillus subtilis than by Lactobacillus and Pediococcus, but Superoxide dismutase (SOD) enzyme activity was higher in ginseng seeds fermented by Lactobacillus and Pediococcus. Conclusion: Antioxidant activities measured by ABTS and SOD were higher in fermented ginseng seeds compared to nonfermented ginseng seeds. These results may contribute to improving the antioxidant activity and quality of ginseng subjected to fermentation treatments.

Modulation of LPS-Stimulated Astroglial Activation by Ginseng Total Saponins

  • Kim, Sok-Ho;Shim, Se-Hwan;Choi, Dea-Seung;Kim, Jong-Hoon;Kwon, Young-Bae;Kwon, Jung-Kee
    • Journal of Ginseng Research
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    • v.35 no.1
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    • pp.80-85
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    • 2011
  • Ginseng, a traditional medicine in Asian countries, is known to prevent various neuropathologic diseases such as Alzheimer's. Ginseng total saponins (GTS) in particular are one of the most effective ginseng extract compounds for neuroprotection. However, their protective effects on astrocytes are rarely reported. In pathological circumstances, astroglial activation plays a pivotal role in neuroinflammation. Subsequently, neuroinflammation induced by activated astrocytes causes brain damage. The purpose of the present study was to determine the suppressive effects of GTS on astroglial activation in lipopolysaccharide (LPS)-stimulated rat primary astrocytes. Astrocytes treated for 24 h with LPS demonstrated suppressed glialfibrillary acidic protein expression in a dose-dependent manner in the presence of GTS. GTS reduced production of proinflammatory cytokines such as tumor necrosis factor-${\alpha}$ and interleukin-1${\beta}$ and inhibited the level of inducible nitric oxide synthase, and cyclooxygenase-2 in LPS-stimulated astrocytes. Furthermore, GTS suppressed intracellular reactive oxygen species production. These modulations due to GTS may indicate neuroprotective antiinfl ammatory properties which may in turn be related to improvements in neurological performance.

Effects of Mixing Ratio on the Mechanical and Thermal Properties of Polyelectrolyte Complex Film

  • Son Tae-Won;Kim Byung-Giu;Park Young-Mi;Lim Hak-Sang;Kwon Oh-Kyung
    • Macromolecular Research
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    • v.14 no.3
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    • pp.267-271
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    • 2006
  • Polyelectrolyte complex films were prepared with two compounds, chitosan and poly(ethylene glycol)-monosuccinate, using a casting in order to synthesize a polyelectrolyte complex film with various mole ratios of chitosan and poly(ethylene glycol)-monosuccinate. The solution properties of isolated PEC were investigated for the effects of FTIR, pH value, Brookfield viscosity and cell viability assay using MTT staining. The PEC films were evaluated for mechanical properties by typical stress-strain curve, far thermal properties by DSC and TGA and for surface morphology Properties by SEM. Furthermore, the surface resistance, moisture regain and water content of the films were characterized. The solution properties were affected by several factors including the chitosan content in the PEC, the mixing ratio of PEG and chitosan, and pH. Several PEC in acidic conditions exhibited film formation under appropriate conditions of mixing ratio and chitosan concentration in the mixing process. These PEC films were found to have sufficiently flexible and stable properties due to their hydrophilic structure, which was farmed by the oppositely charged interaction between PEG-MS and chitosan matrix. The results showed the potential applicability of chitosan and poly(ethylene glycol)-monosuccinate films as a biocompatible polymer.

Effects of newly synthesized benzimidazole derivatives on gastric H^+/K^+$ ATPase

  • Cheon, Hyae-Gyeong;Yum, Eul-Kgun;Kim, Sung-Soo
    • Archives of Pharmacal Research
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    • v.19 no.2
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    • pp.126-131
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    • 1996
  • The effects of various synthetic benzimidazole derivatives on gastric H^+/K^+$ATPase activity in vitro were examined. The results showed that the effects of substituents on the benzimidazole ring were not significant. However, replacement of sulfoxide connecting two ring systems to sulfide resulted in a completely inactive compound in vitro, suggesting the essential role of sulfoxide group in the inhibition. In addition, compounds with 5 or 6-membered oxacyclic substituents attached to the pyridine ring displayed the most effective inhibitory activity. Among these derivatives, AU-47 was the most potent, and detailed mechanistic studies with the compound were carried out. AU-47 inhibited gastricH^+/K^+$ATPase in a concentration and time dependent manner with 50% inhibition at $6\muM$. The presence of sulfhydryl reducing agents or substrate analogue protected H^+/K^+$ATPase from the inactivation. The inhibition by AU-47 was potentiated by acid pretreatment of the compound, suggesting the structural conversion of AU-47 into a more active intermediate which was favored in acidic condition. Consistent with in vitro results, AU-47 inhibited in vivo gastric acid secretion. The results suggest that AU47 is a relevant candidate for the development of new antiulcer agent.

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Electrochemistry of Gallium

  • Chung, Yonghwa;Lee, Chi-Woo
    • Journal of Electrochemical Science and Technology
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    • v.4 no.1
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    • pp.1-18
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    • 2013
  • Gallium is an important element in the production of a variety of compound semiconductors for optoelectronic devices. Gallium has a low melting point and is easily oxidized to give oxides of different compositions that depend on the conditions of solutions containing Ga. Gallium electrode reaction is highly irreversible in acidic media at the dropping mercury electrode. The passive film on a gallium surface is formed during anodic oxidation of gallium metal in alkaline media. Besides, some results in published reports have not been consistent and reproducible. An increase in the demand of intermetallic compounds and semiconductors containing gallium gives rise to studies on electrosynthesis of them and an increase of gallium concentration in the environment with various application of gallium causes the development of electroanalysis tools of Ga. It is required to understand the electrochemistry of Ga and to predict the electrochemical behavior of Ga to meet these needs. Any review papers related to the electrochemistry of gallium have not been published since 1978, when the review on the subject was published by Popova et al. In this study, the redox behavior, anodic oxidation, and electrodeposition of gallium, and trace determination of gallium by stripping voltammetries will be reviewed.