• KSBB Journal
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• v.29 no.2
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• pp.92-97
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• 2014

In this study, we investigate the antimicrobial and antioxidant activities of extracts of Enteromorpha intestinalis. To evaluate the antimicrobial and antioxidant activities, three solvents (hexane, chloroform and methanol) were applied to obtain extracts. The extraction yields are hexane (A) 1.11%, chloroform (B) 0.94%, and methanol (C) 8.2%. Also, the contents of total phenolic compounds of extract A, B, C are 4.03%, 8.15%, and 2.33%, respectively. In the results of antimicrobial activity, extract A and B have higher activity than that of extract C. Especially, Vibrio vulificus, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli are more sensitive than others. In antioxidant activity, extract A and B present the higher DPPH activity than that of control (BHA and ascorbic acid). The DPPH radical scavenging activity and SOD-like activity are ordered as B>C>A. However, extract C show high value in ferric reducing antioxidant power assay. In nitrite scavenging activity, extract A is relatively higher than others. However, the antioxidant activities are lower than that of controls (ascorbic acid and BHA). The antioxidant activities are presented the increasing pattern of increasing by the increasing of extract concentration.

• Preventive Nutrition and Food Science
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• v.11 no.2
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• pp.100-104
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• 2006

The in vitro antimicrobial and antioxidant activities of the essential oil and methanol extracts of Ledum palustre L. were investigated. Using GC-MS analysis, we identified 37 compounds in the essential oil, constituting 87.58% of the total oil. There are several monoterpenes, of which sabinene is the major compound ($16{\sim}17%$). There are several oxygenated monoterpenes of which terpinen-4-ol(7.6%) and myrtenal (3.5%) are the main constituents. $\beta$-Selinene, a-selinene, $\gamma$-elemene, a-caryophyllene are the main sesquiterpenes ($2{\sim}6%$ range). The oil strongly reduced the diphenylpicrylhydrazyl radical ($IC_{50}=1.56{\mu}g/mL$) formation and exhibited a hydroxyl radical scavenging effect in the $Fe^{3+}-EDTA-H_2O_2$ deoxyribose system ($IC_{50}=2.7{\mu}g/mL$), and also inhibited the nonenzymatic lipid peroxidation of rat liver homogenate ($IC_{50}=13.5{\mu}g/mL$). The polar phase of the extract showed antioxidant activity. The oil showed antimicrobial activity against Streptococcus pneumoniae, Clostridium perfringens, Candida albicans, Mycobacterium smegmatis, Acinetobacter lwoffii and Candida krusei while the water-insoluble parts of the methanolic extracts exhibited slight or no activity. This study confirms that the essential oil of Ledum palustre L. possesses antioxidant and low antimicrobial properties in vitro.

• Mycobiology
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• v.37 no.1
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• pp.48-52
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• 2009

Essential oils are mixtures of volatile, lipophilic compounds originating from plants. Some essential oils have useful biological activities including antimicrobial, spasmolytic, antiplasmodial, and insect-repelling activities. In this study, we tested the antimicrobial activity of essential oil prepared from the aromatic plant, Cymbopogon citrates, against three important plant pathogenic and medical microorganisms, Pectobacterium carotovorum, Colletotrichum gloeosporioides, and Aspergillus niger. It effectively inhibited the growth of the bacterium, Pectobacterium carotovorum, in a dose-dependent fashion, and 0.5% of the oil inhibited the growth of bacteria completely. Similarly, the essential oil inhibited the growth of plant pathogenic fungus, Colletotrichum gloeosporioides, and the addition of 1% of essential oil completely inhibited the growth of fungus even after 5 days of culture. Finally, it effectively inhibited the growth of the medically and industrially important fungal species, Aspergillus spp. These results suggest that the essential oil from Cymbopogon citrates may be an environmentally safe alternative to inhibit antimicrobial agents for various uses.

• Biomolecules & Therapeutics
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• v.7 no.3
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• pp.205-209
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• 1999

Stability of the $\beta$-sitosterol glycoside from Schima wallichii sp. at various physical conditions were investigated, mutagenecity of the steroid saponin was determined by Ames test. When exposed in pH 3 to pH 8, the $\beta$-sitosterol glycoside was stable on antimicrobial activity against yeasts. The antimicrobial activity of the $\beta$-sitosterol glycoside also stable in high temperature, $N_2$, $O_2$ gas and light exposure, and metal ion. Ames test result revealed that $\beta$-sitosterol glycoside did not have any mutagenic activity. These results suggest that the $\beta$-sitosterol glycoside might be a promising candidate as a natural antimicrobial compound.

• Natural Product Sciences
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• v.24 no.3
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• pp.159-163
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• 2018

Two new polyketides, chinoketides A and B (1 - 2) with a known compound xylarphthalide A (3), were isolated from the solid medium of the endophytes from the leaves of the relic plant Distylium chinense with the "black-box" co-culture method, and the structures of two new compounds were elucidated by NMR, MS and CD spectra. And the absolute configurations of chinoketides A (1) and B (2) were determined as 2R,3R,8S and 5R,6S by calculating their ECD spectra to compare with the experimental CD spectra. Finally, the antimicrobial activities were evaluated to Erwinia carotovora sub sp. Carotovora (Jones) Bersey et al, and the results showed that compounds 1 - 3 displayed the antimicrobial activities with MIC value at 20.5, 30.4 and $10.2{\mu}g/mL$.

• Food Science and Preservation
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• v.5 no.3
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• pp.281-285
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• 1998

Methanol extract and various solvent fractions from Moutan Cortex were tested for their antimicrobial activities, free radical scavenging activities and antioxidative activities, and phenolic compounds in ethylacetate fraction were analyzed by GC and HPLC. In the antimicrobial activities test, the ethylacetate fraction of methanol extract showed stronger than other fractions. The antimirobial activities were more effective against Gram positive bacteria than Gram negative bacteria. Minimum inhibitory concentration(MIC) of ethylacetate fraction showed 156-1250$\mu\textrm{g}$/ml against Cram positive bacteria and 2500-5000$\mu\textrm{g}$/mg against Gram negative bacteria. The free radical scavenging activities and antioxidative activities using linoleic acid were higher in ethylacetate fraction. The antioxidative activity of ethylacetate fraction was similar to ${\alpha}$-tocopherol. The 3 major phenolic compounds were analyzed by GC and HPLC and these content were determined. The content of p-hydroxybenzoic acid, methyl gallate and gallic acid were 1.35%, 14.61% and 4.01%, respectively.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.306-311
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• 2011

This study was performed to investigate the effect of Portulaca oleracea extract on the antioxidant and antimicrobial activities against Helicobacter pylori. The each solvent extracts prepared from Portulaca oleracea were investigated by measuring total phenolic compounds, electron donating ability, superoxide dismutase-like ability and thiobarbituric acid reactive substances The herb extractor extract yielded the highest content of total phenolic compounds(72.2 mg%). The electron donating abilities(EDA) of ethyl acetate and methanol extracts showed high antioxidant activity. The superoxide dismutase (SOD)-like abilities of ethyl acetate and petroleum ether extracts also showed some activity. The antioxidant activity of thiobarbituric acid reactive substances was not significant. The petroleum ether extract of Portulaca oleracea showed the highest antimicrobial activity at 10,000 ppm concentration.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.81-86
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• 2006

This study was carried out to investigate the antimicrobial and antioxidant activities for applications of food additives and medicine using Rumex crispus which widely grown in domestic area. Antimicrobial activities of extract fractions were observed in all microbial species except for Pseudomonas areuginosa. Especially, Vibrio vulificus and Saccharomyces cerevisiae presented obvious antimicrobial activity. Antioxidant activities of the fractions of R. crispus extract were determined by DPPH radical scavenger activity. The fraction of ethyl acetate was presented similar antioxidant activities compared with that of BHA and ascorbic acid. Also, ethyl acetate fraction contained higher phenolic compounds than that of others. The antioxidant activity in the fractions of R. crispus extract was closely related with the content of phenolic compounds in that.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.193-197
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• 1989

The three new Alkylene bisdithionreido $\beta$-lactam derivatives were synthesized and evaluated for antimicrobial activities. Treatment of cefadroxil.2DMF with alkylene diisothiocyanate which was obtained by the reaction of alkylene diamine with carbon disulfide, sodium hydroxide and ethyl chloroformate afforden alkylene bisdithioureido $\beta$ -lactam derivatiives. The antimicrobial activities of the compounds synthesized were ethylene bisdithioureido $\beta$-lactam derivative lost the sensitivity against Escherichia coli but showed potent antimicrobial activity against $\beta$-lactams Escherichia coli, but, tetramethylene bisdithioureido $\beta$-lactam derivative and hexamethylene bisdithioureido $\beta$ -lactam derivative compounds showed diminished or no antimicrobial activities.

• Food Science and Preservation
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• v.11 no.2
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• pp.207-213
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• 2004

Methanol extracts were prepared from 32 medicinal herbs of the extracts were tested their microbial inhibition activities against food borne pathogens and/or food poisoning microorganisms, food-related bacteria and yeast. Methanol extracts of Cinnamomum cassia, Paeonia suffruticosa, Alnus japonica, Eugenio caryophyllata and Illicium verum exhibited antimicrobial activity for the microorganisms tested, except lactic acid bacteria and yeast. Minimum inhibitory concentrations(MIC) were about 5 mg/mL for Bacillus subtilis, Staphylococcus epidermidis and Pseudomonas aeruginosa. Cell growth of lactic acid bacteria was inhibitied, but greatly on Leuconostoc mesenteroides. The phenolic compound contents were 10.98 mg/g, 10.31 mg/g, 8.55 mg/g and 6.69 mg/g in Thea sinensis, Eugenia caryophyllata, Alnus japonica and Artenisia capillaris, respectively. Antimicrobial activity appeared to be related to phenol compound content in medicinal herbs. The methanol extracts of medicinal herbs could be suitable for the development of a food preservative.