• Journal of Life Science
• /
• v.23 no.5
• /
• pp.637-642
• /
• 2013

This study was performed to evaluate the rodent repellency and antimicrobial activity of natural oils. Thirteen natural essential oils were evaluated for repellent efficacy against rodent feed intake suppression activity. Salvia sclarea (sage), Cinnamomum zeylanicum (cinnamon) Cymbopogon citratus (lemon grass), and Syzygium aromaticum (clove) showed the best repellent efficacy among tested natural oils. Antimicrobial activity against Gram-negative (four strains) and Gram-positive (four strains) bacteria were evaluated using four natural oils, which showed high efficacy on the rodent repellent test. Syzygium aromaticum showed antimicrobial activity against all tested bacteria and Cymbopogon citratus, Cinnamonum zeylanicum, and Salvia sclarea showed antimicrobial activity against some tested bacteria.

• Korean journal of food and cookery science
• /
• v.14 no.1
• /
• pp.114-118
• /
• 1998

In ordo. to develop the natural food preservative agent, freeze dried dandelion (Taraxcum platycarpum) was extracted with several solvents, and antimicrobial activity was investigated. The methanol extract obtained from the dandelion exhibited antimicrobial properties against five strains such as Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Vibrio parahaemolyticus. The methanol extract at the concentration of 2000 $\mu\textrm{g}$/ml completely inhibited the growth of B. subtilis, E. coli, L. monocytogenes and V. parahaemolyticus. Antimicrobial activity of the ethylacetate fraction from the methanol extract of dandelion was the strongest fraction compare to those the other solvent fractions such as n-hexane, chloroform, n-butanol and water. The ethylacetate fraction showed the inhibitory effect at the concentration of 0.5 mg/disc on the growth of the food spoilage microorganisms.

• YAKHAK HOEJI
• /
• v.17 no.3
• /
• pp.147-151
• /
• 1973

Fifteen thiosemicarbazone derivatives were synthesized and evaluated for their antimicrobial activity against Staphylococus aureus, Escherchia coli and Pichia sp. Anticancer activity in vitro was also tested against human carcinoma HeLa cells.

• Korean Journal of Veterinary Research
• /
• v.43 no.4
• /
• pp.625-631
• /
• 2003

The extracts from 40 different traditional medicinal herbs were used to investigate the antimicrobial activities against Escherichia coli. Among them, the extracts from Paeonia suffruticosa (PS), Siegesbeckia orientalis (SO), Schizandra chinensis (SC), Caesalpinia sappan (CS) and Rhus javanica (RJ) exhibited high antimicrobial activities against E. coli, Minimum inhibitory concentrations (MIC) of the RJ extract against E. coli were 0.8 mg/ml. After heating treatment of these extracts, the antimicrobial activities against E. coli were significantly reduced in case of the CS extract. After alkaline or acid treatment of these extracts, the antimicrobial activities against E. coli were significantly increased in the PS extract but reduced in both SO and RJ extract. Since extracts from RJ and CS exhibited the highest antimicrobial activities, bacterial growth-inhibiting activities against E. coli by these two extracts were further examined. Optical density at 620 nm after 24 hours incubation of E. coli in the presence of 100, 300 or 500 ppm of RJ extract ranged from 0.1 to 0.2 compared to 0.35~0.65 in the absence of RJ extract, indicating that growth of E. coli was significantly inhibited within 24 hours by the addition of at least 100 ppm of RJ extract. Optical density at 620 nm after 24 hours incubation of E. coli in the presence of 300 or 500 ppm of CS extract ranged from 0.01 to 0.25 compared to 0.5~0.55 in the absence of CS extract, indicating that growth of E. coli was also significantly inhibited within 24 hours by the addition of at least 300 ppm of CS extract. In conclusion, these findings suggest that extracts from RJ and CS may play important roles for antimicrobial activities against E. coli causing various animal diseases.

• Journal of Korean society of Dental Hygiene
• /
• v.12 no.1
• /
• pp.81-91
• /
• 2012

Objectives : By investigating antimicrobial activity of natural extracts, identifying its usefulness as antibiotic material to oral bacteria. Methods : Antimicrobial activity tests of 25 natural extracts were implemented on 6 type strains alleged to cause dental caries and 10 clinical strains isolated and identified from dental caries. Results : Among medicinal plants, Coptis japonica, Scutellaria baicalensis, Dictamnus dasycarpus showed antimicrobial activity. Among lichens, 3 methanol extracts and 6 acetone extracts showed antimicrobial activity. Minimum Inhibitory Concentration(MIC) test of Usnea aurantiacoatra KoLRI 004184, an acetone extract of lichen with the highest antimicrobial activity, on 6 type strains involved in dental caries and 10 strains isolated from dental caries resulted as follows; Actinomyces oris 1041 $12{\mu}g/ml$, for Corynebacterium durum 3151 $13{\mu}g/ml$, for Rothia dentocariosa KCTC $3204^T$ $14{\mu}g/ml$, for R. dentocariosa 911 $15{\mu}g/ml$, for R. dentocariosa 1822 $12{\mu}g/ml$, for Lacto-bacillus casei KACC $12413^T$ $12{\mu}g/ml$, for L. acidophilus KACC $12419^T$ $16{\mu}g/ml$, for L. rhamnosus 2421 $15{\mu}g/ml$, for Streptococcus mutans KCTC $3065^T$ $15{\mu}g/ml$, for S. mutans 121 $13{\mu}g/ml$, for Streptococcus oralis 2221 $18{\mu}g/ml$, for S. salivarius KCTC 5512 $14{\mu}g/ml$, for S. salivarius 122 $12{\mu}g/ml$, for S. sanguinis KCTC $3284^T$ $14{\mu}g/ml$, for S. sanguinis 912 $14{\mu}g/ml$, for Neisseria sp. KEM232 $12{\mu}g/ml$. Conclusions : Even a small amount of extract from lichen Usnea aurantiacoatra KoLRI 004184 showed very high level of antimicrobial activation against all 16 bacterial strains involved in dental caries.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.3
• /
• pp.349-354
• /
• 2006

Furaneol, a key aroma compound found in strawberry, pineapple, and processed foodstuffs, has been known to possess various biological activities on animal models. In this study, the antimicrobial effects of furaneol against human pathogenic microorganisms were investigated. The results indicated that furaneol displayed a broad spectrum of antimicrobial activities against Gram-positive and Gram-negative bacteria and fungi without hemolytic activity on human erythrocyte cells. To confirm the antifungal activity of furaneol, we examined the accumulation of intracellular trehalose as a stress response marker on toxic agents and its effect on dimorphic transition of Candida albicans. The results demonstrated that furaneol induced significant accumulation of intracellular trehalose and exerted its antifungal effect by disrupting serum-induced mycelial forms. These results suggest that furaneol could be a therapeutic agent having a broad spectrum of antimicrobial activity on human pathogenic microorganisms.

• Korean Journal of Food Science and Technology
• /
• v.27 no.2
• /
• pp.216-220
• /
• 1995

In order to investigate the possible use of vegetable kimchi stuff as natural preservatives for kimchi, the methanol extracts of 15 kinds of vegetable kimchi stuff were solvent-fractionated and fractions were tested for antimicrobial activities against Leuconostoc mesenteroids, Pediococcus cerevisiae, Lactobacillus plantarum and Saccharomyces cerevisiae. The neutral fractions of the extracts of garlic and leek showed strong antimicrobial activities. The extract of leek showed particularly strong antimicrobial activities against Ped. cerevisiae and L. plantarum that were known to be main microorganism of fermentation and acidification of kimchi. The results suggest the possible use of the leek extract as natural preservatives for kimchi.

• Food Science and Preservation
• /
• v.7 no.1
• /
• pp.1-7
• /
• 2000

To develop natural antimicrobial agents for keeping qualities of postharvested greenhouse produce the antimiocrobial actions of Polygonum cuspidatum Sieb. et Zucc. extract , which showed remarkable antimicrobial effects against microorganism causing the postharvest decay of greenhouse produce, were investigate. In the inhibitory experiment of enzymes related to energy production metabolism hexokinase activities decreased to 73% and 68% by treating with Polygonum cuspidatum Sieb. et.Zucc. extract and Eugenia caryophyllata Thumnberg extract in comparison with control, respectively. Direct visualization of microbial cells by using both transmission electron microscope and scanning electron microscope showed that microbial cell membrane was destroyed by treating with the dilute extract solution. this change of celluloar membrane permeability could be identified in the experiment that 0-nitrophenyl-${\beta}$-D-galactopyrano-side(ONPG), the artificial substrate of ${\beta}$-galactosidase, was hydrolyzed in the presence of the extract, indicating that the membrane was perturbed. The separation and identification of the most antimicrobialo substances isolated from Polygonum cuspidatum Sieb et. Zucc. extract and Eugenia caryophyllata Thunberg extract were carried out by using gas chromatography and mass spectrometry 9GC/MSD), which were identified as eugenol. As a result, the functionality of Polygonum cuspidatum Sieb. et Zucc. extract and Eugenia caryophyllata Thunberg extract as antimicrobial agents for keeping qualities of postharvested greenhouse produce may be recommended.

• Natural Product Sciences
• /
• v.24 no.3
• /
• pp.159-163
• /
• 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 $10.2{\mu}g/mL$.

• Journal of Food Hygiene and Safety
• /
• v.10 no.3
• /
• pp.139-145
• /
• 1995

In order to develop a natural food preservative, the root bark of Morus alba was extracted with several solvents, and then antimicrobial activity was investigated. The optimum extracting condition for the antimicrobial substance from the sample, minimum inhibitory concentration (MIC) of the extracted substance against microorganisms were also examined. The antimicrobial activity of the ethanol extract form the sample was stronger than those of the extracts by the other solvents such as water, methanol. ethyl acetate and acetone. The optimum extracting condition for antimicrobial substance from the sample was shaking extraction twice for 5 hours at room temperature in case of 7 times of absolute ethanol added to the crushed root bark of Morus alba. The ethanol extract from the root bark of Morus alba had strong B. cereus, L. monocytogenes and S. aureus. Especially, Bacillus species was the most susceptible to the extracted substance. The ethanol extract showed antimicrobial activity against Gram negative bacteria(MIC, 160~1600 ug/ml) and yeasts(MIC, 1600 ug/ml) such as C. albicans and S. acidifaeciens. The extract also showed growth inhibition against molds such as A. niger, A. parasiticus, A versicolar and T. viride.