• Microbiology and Biotechnology Letters
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• v.40 no.1
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• pp.66-69
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• 2012

Five strains out of 200 candidate strains (SG 1-9, 1-12, SG 2-8, 2-10, and 2-17) were selected to determine their antifungal activity against Raffaelea quercus-mongolicae. The 16S rDNA sequences of the five strains were determined by sequencing analysis and analyzed by the homology of the blast program at NCBI. The homology search showed that SG 1-9 and 1-12 had a 98% homology with Streptomyces cinnamoneus and 98% homology with Burkholderia cepacia, while SG 2-8, 2-10, and 2-17 had a 99% homology with Streptomyces fradiae, a 97% homology with Staphylococcus epidermidis, and a 99% homology with Staphylococcus epidermidis. Out of the five selected strains, organic extract and protein extracts of SG2-17 strain broth were employed to determine antifungal activity against Raffaelea quercus-mongolicae. The organic extract exhibited antifungal activity, but the protein extracts did not demonstrate such an activity. Three organic solvents, butanol, benzene, and ethyl acetate, were also used for determination of antifungal activities. The activity measurements revealed that benzene extract possessed the greatest inhibitory effect on the growth of Raffaelea quercus-mongolicae, with the next highest being butanol extract, and ethyl acetate extract being the lowest.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.111-114
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• 2004

This study was carried out to evaluate the inhibition of growth and collagenase activity of Salvia miltiorrhiza Bunge against microorganisms causing periodontal diseases. The ethanol extract of Salvia miltiorrhiza showed sig-nificant growth inhibition against microorganisms causing periodontal diseases. Ethanol extract was further fractionated with organic solvents in the order of hexane, chloroform and ethyl acetate. Among the fractions tested, the hexane fraction showed the highest cell growth inhibition. The minimal inhibitory concentration (MIC) of the extract against C. curvus, C. rectus, E. corrodens, F nucleatum, P. gingivalis, P. intermedia and W. succinogenes were 200, 50, 50, 250, 150, 250 and 200 ${\mu}g$/ml, respectively. The inhibition of collagenase activity by organic solvent fractions were higher than that of minocycline, and the inhibition ratio of collagenase activity was $88.2{\pm}2.1$ % in the chloroform fraction.

• Korean Journal of Materials Research
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• v.34 no.2
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• pp.95-104
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• 2024

Nanoparticles are commonly used to avoid the opaque white color of TiO₂ based sunscreen. However, a dispersing agent is typically required because of the tendency of the nanoparticles (NPs) to agglomerate. Stearic acid is one kind of dispersing agent often used for sunscreen products. However, according to the MSDS data sheet on stearic acid, stearic acid is highly hazardous to aquatic life and causes irritation on human skin. To avoid this problem, in this study a safer organic dispersing agent extracted from Korean seaweed has been studied to disperse TiO₂ nanoparticles, and further use as an active agent in sunscreen products. The presence of phytochemicals in seaweed extract, especially alginate, can disperse TiO₂ nanoparticles and improve TiO₂ dispersion properties. Results show that seaweed extract can improve the dispersion properties of TiO₂ nanoparticles and sunscreen products. Reducing the agglomeration of TiO₂ nanoparticles improves sunscreen properties, by making it less opaque white in color, and increasing UV protection value. It was also confirmed that adding seaweed extract into sunscreen products had no irritating effects on the human skin, making it more desirable for cosmetics application.

• Korean Journal of Organic Agriculture
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• v.23 no.3
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• pp.567-582
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• 2015

Botrytis cinerea infects stems, leaves and fruits of greenhouse tomato and can cause serious economic losses. This study was conducted to develop organic farming control method against tomato gray mold. Twenty two organic farming materials including mineral and plant extracts were screened for the suppressive activity against Botrytis cinerea, in vitro and in vivo. Among the organic farming materials, sulfur, copper, Chinese twinleaf extract and rhubarb extract decreased by 51.7-90% of the spore germination of Botrytis cinerea. Also, gray mold incidence was reduced more than 90% on tomato stems by treating sulfur, seaweed extracts, rhubarb root extracts and Chinese twinleaf extract. After the selected four organic farming materials were applied on tomato cultivated in greenhouse, their control effects against the tomato gray mold were tested. When the water soluble sulfur was foliar-sprayed on the tomato leaves infected by artificial inoculation with spore suspension of Botrytis cinerea, it showed 87.9% of control value. Also, control activity of the water soluble sulfur was paralleled with chemical fungicide, diethofencarb+carbendazim. The above mentioned results indicate the sulfur formulation can be used as chemical fungicide alternatives for controlling tomato gray mold in the greenhouse.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.349-354
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• 2004

The extracts of Pinus densiflora sawdust by n hexane, ethyl acetate and methanol solvent were investigated to identify their mycelial growth inhibition against Lentinus edodes. The yields of n hexane soluble fraction, ethyl acetate-soluble fraction, and methanol soluble fraction from P. densiflora sawdust were obtained 1.36%, 2.21% and 4.03% using organic solvent, respectively. The mycelial growth inhibition of L. edodes was the greatest for n hexane extract, ranging from 36.5% to 47.6% at concentrations of 125 ppm to 1,000 ppm, with the values for all concentrations significantly different from one another. After direct extraction of P. densiflora sawdust using n hexane, ethyl acetate and methanol, each extract was separated into three fractions by silica gel column chromatography and then the fractions were isolated on the values of $R_f$ by thin layer chromatography. The mycelial growth inhibition against L. edodes was recognized in the fractions II (33.5%) and III (37.6%) of n hexane extract, the fraction II (21.4%) of ethyl acetate extract and the fraction II (26.4%) of methanol extract. The fractions III of n-hexane extract showed the highest growth inhibition among the nine fractions of the organic solvent extract.

• Preventive Nutrition and Food Science
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• v.18 no.1
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• pp.50-59
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• 2013

Black jujube was made by aging dried jujube and its physiochemical characteristics, antioxidant activities and ${\alpha}$-glucosidase inhibitory activities were evaluated. The moisture and sugar contents were increased depending on the period of aging times and the pH was reduced thereby increasing acidity. The color of black jujube extract was changed from red to black resulting in decreases of Hunter color values L, a and b. As the aging progressed, sucrose was decomposed by increasing glucose and fructose, indicating higher contents of the total reducing sugars. Among the six different types of organic acids extracted from dried jujube, the levels of oxalic acid and citric acid were increased as the aging progressed. The total polyphenol contents in ethanol and water extracts of dried jujube were 7.74 and 8.12 mg/g, respectively. The water extract of black jujube aged for 48 hr contained the highest polyphenol contents at 16.82 mg/g. The 5'-hydroxymethylfurfural (5'-HMF) contents of black jujube extract significantly increased by longer aging times, and contained higher contents in the ethanol extract than water extract. The ethanol extract of black jujube showed the highest 5'-HMF content with 338.89 mg% after aging for 3 days. Also, $IC_{50}$ values of black jujube aged for 72 hr evaluated by DPPH and ABTS radical assays were 0.54 and 0.59 mg/mL, respectively. ${\alpha}$-Glucosidase inhibitory activities of black jujube at the concentration of 3.33 mg/mL (ethanol extract) increased from 65 to 80 % after aging for 72 hr.

• Korean Journal of Organic Agriculture
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• v.30 no.3
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• pp.393-407
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• 2022

The effect of Neobacillus sp. JC05 extract on the defense response in cucumber plants against root-knot nematode (RKN) was evaluated. As a result of drench treatment of JC05-extract in cucumber plants, formation of egg mass per plants and disease severity were significantly decreased compared to untreated control plants; the malondialdehyde contents also decreased in JC05-extract treated plants. When eggs of Meloidogyne incognita were inoculated, cucumber plants treated with JC05-extract elevated pathogenesis-related gene expression such as chitinase and lipoxygenase, these are well known as inducing resistance in plants, in addition, peroxidase among antioxidant enzymes was significantly activated. Moreover, the JC05-extract enhanced FDAse activity in soils grown cucumber plants inoculated by eggs of M. incognita. Taken together, these results suggest that the JC05-extract could involve in activation of defense-related mechanisms of cucumber plants and result in decrease of disease occurrence caused by M. incognita.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.215.2-216
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• 2003

Velutin and betulinic acid were isolated as a cytotoxic principle from the dichloromethane extract of Korean mistletoe (Viscum album var. coloratum) by repeated silicagel chromatography and recrystallization. In in vitro analysis of cytotoxic activity using NIH-3T3 cells, dichloromethane extract of Korean mistletoe was shown to be highly cytotoxic against tumor cells. And we obtained active compound (reffered to VD-2 and VD-6) from the dichloromethane extract. (omitted)

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.288-293
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• 2002

Allergen-removed-extract was produced from Rush verniciflua by two phase methods. Phase one was high temperature treatment of Rush verniciflua tree to get allergen-removed-extract. Phase two was extraction of solution from phase one product using water or organic solvents. The solutions from above method show high antioxidant activity, anticancer activity, and improvement in lung function, but did not contain urushiol family compounds.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.705-718
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• 2014

This study was performed to evaluate the suppressive effects of organic fungicides made using environment-friendly materials on leaf spot disease and anthracnose that infect ginseng. Anthracnose (Colletotrichum gloeosporioides) and leaf spot disease (Alternaria panax) are principal diseases that decrease the yield of ginseng by defoliation before root enlargement. Fermented eggs and oyster shells, water extract of green tea and ethanol extract of red ginseng dregs were significantly effective in suppressing leaf spot disease. Fermented crab and shrimp shells and fermented motherwort were also effective in suppressing the recurrence of ginseng anthracnose. The preventive effects of these environment-friendly materials were definitely superior to the therapeutic effects. Therefore, these materials could be used as alternatives to chemical pesticides, which can not be applied in organic ginseng cultivation field. These organic fungicides need to be applied before the incidence of ginseng anthracnose in order to maximize their suppressive effects.