• CELLMED
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• v.4 no.1
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• pp.5.1-5.8
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• 2014

Healthcare-associated infection represents a frequent cause of mortality that increases hospital costs. Due to increasing microbial resistance to antibiotics, it is necessary to search for alternative therapies. Consequently, novel alternatives for the control of resistant microorganisms have been studied. Among them, plant antimicrobial protein presents enormous potential, with flowers being a new source of antimicrobial molecules. In this work, the antimicrobial activity of protein-rich fractions from flower tissues from 18 different species was evaluated against several human pathogenic bacteria. The results showed that protein-rich fractions of 12 species were able to control bacterial development. Due its broad inhibition spectrum and high antibacterial activity, the protein-rich fraction of Hibiscus rosa-sinensis was subjected to DEAE-Sepharose chromatography, yielding a retained fraction and a non-retained fraction. The retained fraction inhibits 29.5% of Klebsiella pneumoniae growth, and the non-retained fraction showed 31.5% of growth inhibition against the same bacteria. The protein profile of the chromatography fractions was analyzed by using SDS-PAGE, revealing the presence of two major protein bands in the retained fraction, of 20 and 15 kDa. The results indicate that medicinal plants have the biotechnological potential to increase knowledge about antimicrobial protein structure and action mechanisms, assisting in the rational design of antimicrobial compounds for the development of new antibiotic drugs.

• Journal of Food Hygiene and Safety
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• v.18 no.4
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• pp.189-194
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• 2003

Approved chemical preservatives have been widely used to preserve foods and increase their shelf life. There are increasing demends of the partial or complete removal of chemical preservatives from foods vecause of adverse health effect of chemicals. In this study, the possibility of natural antimicrobial compounds, Korean propolis as food preservatives are investigated. Propolis samples were extracted on various concentration of ethanol. Propolis extracts extracted with 100% ethanol showed the highest inhibitory effect aginst food spoilage microorganisms. The 100% ethanol extracts of propolis were selected and the antimicrobial activites of 100% ethanol extracts of proplis against several food spoilage microorganisms were examined. Bacillus subtilis, Micrococcus luteus, Escherichia coli, Staphylcoccus aureus, Bacillus cereus, Shigella sonnei, Salmonella choleraesuis, Erwinia rhapontici, and Vibrio parahaemolyticus as food poisoning microorganisms were chosen for the examination. The Propolis extracts had antimicrobial activity against food spoilage microorganisms. When the microorganisms were treated with propolis extracts, the population of food spolige microorganisms were decreased by 1~9 log.

• The Korean Journal of Food And Nutrition
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• v.27 no.4
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• pp.609-618
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• 2014

We evaluated the yield of extract, antioxidant compounds (total phenolic, total flavonoid), antioxidant (DPPH assay, ABTS assay, Oyaizu's assay, FRAP assay), and antimicrobial activities of Siraegi (dried radish greens) according to cooking process (non-blanched, blanched, seasoned). The yield of non-blanched Siraegi was 4.91%, blanched Siraegi was 0.33%, and seasoned Siraegi was 7.55%. In total polyphenol and flavonoid contents, seasoned Siraegi extracts showed higher antioxidant compounds ($129.85{\pm}0.62mg$ GAE/100 g FW, $35.56{\pm}1.19mg$ CHE/100 g FW) than non-blanched and blanched. Total antioxidant activities (DPPH assay, ABTS assay, FRAP assay, reducing power) were shown to be in the order of seasoned Siraegi > non-blanched Siraegi > blanched Siraegi. In antimicrobial activity, non-blanched Siraegi (5, 10 mg/disc) showed antimicrobial activity against B. cereus, E. cloacae, and E. coli (9.25 mm), and P. aeruginosa (9 mm) at 10 mg/disc. In terms of antimicrobial activity, non-blanched Siraegi was good but eating the dried vegetable was difficult so it is essential to blanch it. Also, with many added seasonings in the process of cooking, it can be easy to eat. Overall, the results of this study demonstrate that cooked Siraegi with seasoning would be the most efficient way of ingesting the antioxidant material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.663-669
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• 2007

The solvent extracts of Sargassum muticum, which were extracted by using several solvents with different polarities, were prepared for use as natural preservatives. The S. muticum extract with 80% ethanol was sequentially fractionated with n.hexane, dichloromethane, ethylacetate, and butanol. In order to effectively screen for natural preservatives agents, we first investigated the antioxidant activities such as DPPH radical scavenging capacity, superoxide radical scavenging capacity, and xanthine oxidase inhibitory activity of the S. muticum extracts. Through the screening system, we found that dichloromethane and ethylacetate fraction had high antioxidant activity with increments of the extract concentration. The antimicrobial activities and cell growth inhibition were investigated for each strain with the different concentrations of S. muticum extracts. Antimicrobial activities were shown in ethanol, dichloromethane, and n.hexane fractions of S. muticum. However, butanol, ethylacetate and water fractions showed weak antimicrobial activity against the tested microorganisms. Among the five fractions, dichloromethane fraction showed the highest antimicrobial activities against microorganisms tested, such as Bacillus sublitis, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella Enteritidis and Pseudomonas aeruginosa. The polyphenolic compounds from ethanol, n.hexane, dichloromethane, ethylacetate, butanol, and water fractions were 63.96 mg/g, 8.49 mg/g, 28.11 mg/g, 172.64 mg/g, 114.56 mg/g, and 34.91 mg/g, respectively. The dichloromethane fraction could be suitable for development as a food preservative.

• Journal of Life Science
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• v.22 no.8
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• pp.1071-1076
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• 2012

To investigate the antimicrobial and anti-halitosis effects of Alnus firma extracts and gallic acid (GA) isolated from A. firma, we measured their antimicrobial activities against oral pathogens and their inhibitory effects on the cell adhesiveness and acid production of oral pathogens. In addition, the levels of volatile sulfur compounds were determined by using oral chroma. The dichloromethane (DCM) fraction has broad antimicrobial activity, and the ethylacetate (EA) fraction showed a relatively high level of antimicrobial activity against Streptococcus mutans and Porphyromons gingivalis. Especially, the GA and DCM fractions had significant inhibitory effects on the attachment and acid production of S. mutans and Streptococcus salivarius, respectively. The 2% MeOH extract of A. firma showed a significant inhibitory effect on the production of volatile oral compounds, such as hydrogen sulfide, methyl mercaptan, and dimethyl sulfide, which can cause bad breath and halitosis. Two percent GA also had a significant inhibitory effect on the production of hydrogen sulfide. Our study showed that the active fractions and GA of A. firma could be suitable resources for development as a natural antibiotic agent for the treatment of infectious oral diseases.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.112-117
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• 2008

This experiment was carried out to obtain the basic information on processing for product of high quality goods in Artemisia capillaris. We investigated antioxidant and antimicrobial activities by harvesting date and plant parts in Artemisia capillaris. Contents of total polyphenol compounds and flavonoids were the highest in leaf, followed by capitulum and stem. Leaf on June 30 contained 76.7 mg/g DW total phenolic compounds and 78.2 mg/g DW flavonoids. As $RC_{50}$ value, that was, the concentration of sample required for 50% reduction of DPPH (2,2-diphenyl-l-picrylhydrazyl) absorbance, was very low as $5.42\;{\mu}g$ in leaf on June 30, antioxidant activity was the highest. In addition, $RC_{50}$ of BHA, BHT and ${\alpha}-tocopherol$ were $3.09\;{\mu}g$, $24.30{\mu}g$ and $2.87{\mu}g$, respectively. And capitulum had antimicrobial activities against Bacillus subtilis, Staphylococcus aureus, Enterobacter aerogenes, Citrobacter freundii, Vibrio vulnificus, Pseudomonas aeruginosa, Saccharomyces cerevisiae. By the way, leaf and stem rarely had antimicrobial activity. Antimicrobial activities of capitulum according to harvesting date were very various. Capitulum on August 30 had the highest antimicrobial activities against Bacillus subtilis, Staphylococcus aureus, Vibrio vulnificus, Saccharomyces cerevisiae and on July 30 against Enterobacter aerogenes, Citrobacter freundii, Pseudomonas aeruginosa.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.469-481
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• 2014

IIn vitro antimicrobial and anti-inflammatory activities of nargenicin and its derivatives were investigated. Nargenicin, an unusual macrolide antibiotic with potent anti-MRSA (methicilin-resistant Staphylococcus aureus) activity, was purified from the culture broth of Nocardia sp. CS682. And variety of novel nargenicin derivatives was synthesized from nargenicin. Two compounds (4 and 5) exhibit a broad spectrum of antimicrobial activities against infectious bacteria. The antimicrobial activity of derivatives against fifteen organisms was assessed using the minimum inhibitory concentration (MIC). The MIC values were in the ranges of $0.15{\sim}80{\mu}g/mL$ (w/v) for compound 1 and 2, $5{\sim}80{\mu}g/mL$ (w/v) for compound 3, $1.25{\sim}40{\mu}g/mL$ (w/v) for compound 4, and $1.25{\sim}80{\mu}g/mL$ (w/v) for compound 5, depending on the pathogens studied. In vitro, we investigated cytotoxicity and inhibition of nitric oxide (NO) production of synthesized compounds 1-5 in Raw 264.7 cells. LPS-induced nitric oxide releases were significantly blocked by compound 3, 4 and 5 in a dose-dependent manner. At high concentrations ($5{\mu}g/mL$) compound 5 inhibited the NO production by 95%. Compound 4 inhibited the release of NO in LPS-activated Raw 264.7 cells by 75% at the concentration of $10{\mu}g/mL$. Compound 3 inhibited the release of NO in LPS-activated Raw 264.7 cells by 65% at the concentration of $100{\mu}g/mL$. On the other hand, nargenicin, compound 1 and 2 did not inhibit NO production. These results demonstrated that compound 4 and 5 displayed antimicrobial activity and blocked LPS-induced pro-inflammatory mediators such as NO in macrophages, which might be responsible for its therapeutic application.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.159-165
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• 2003

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.19-23
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• 1990

A series of hexahydro-s-triazine derivative were prepard. Cytotoxic activity testing using mouse leukemia cells (p 388) and antimicrobial testing indicated that the compounds which contain isoxazolyl moiety higher activity than those containing other hetercyclic moieties.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.59-59
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• 2020