• Applied Biological Chemistry
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• v.27 no.2
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• pp.100-106
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• 1984

Five subcellular fractions were obtained by successive centrifugation from the liver of rats within 6 hours of life and characterized by comparing marker compound or marker enzyms. After incubating $3{\beta}$-hydroxy-$5{\alpha}$-pregnan-20-one with the each fraction, the steroids were analyzed by TLC, GLC and GC-MS. A $6{\alpha}$-hydroxylase which hydroxylizes the tetra-hydrogenated compound of progesterone, $3{\beta}$-hydroxy-$5{\alpha}$-pregnan-20-one, was localized in the crude plasma membrane fraction, but not in the microsome fraction. The maximum 6α-hydroxylation was observed at pH 7.0. While this 6α-steroid hydroxylase was not able to hydroxlyze the progesterone, the $3{\alpha}$-isomer was hydroxylized at the $6{\alpha}$-position.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.49-57
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• 2000

To understand the effects of drying conditions on changes of volatile compounds in fruits of Schizandra chinensis, we analyzed SDE (steam distillation and extraction) extract and Headspace vapor of fresh and dried samples using GC/MS (Gas chromatograph/Mass spectrometer). Contents of essential oils from samples with different drying conditions were 0.58% in fresh ones, 0.60% in freeze dried ones, and 0.30% in hot-air dried ones. In SDE extract, major volatile compounds in fresh samples were terpinen-4-ol(9.01%), ${\gamma}-terpinene(7.02%),\;{\beta}-myrcene(7.55%)$, unidentified sesquiterpenes(28.48%), showing almost the same composition as that in freeze-dried ones, but those in hot-air dried samples at $60^{\circ}C$ were ${\gamma}-terpinene(5.40%),\;{\alpha}-elemene(8.28%)$, unidentified sesquiterpenes(50.38%), indicating the chemical changes during drying procedure. In Headspace vapor, major compounds in fresh samples were ${\beta}-myrcene(22.05%),\;{\gamma}-terpinene(9.47%),\;{\alpha}-pinene(8.91%)$, sabinene(8.48%), which were different from those in SDE extract. In chemical compositions of volatile compounds in dried samples, ${\beta}-myrcene,\;{\alpha}-terpinene$ decreased in the order of freeze-drying > hot-air drying at $60^{\circ}C$ > hot-air drying at $60^{\circ}C$, and ${\alpha}-ylangene,\;{\alpha}-pinene$, camphene increased in the reverse order of the former. We observed the changes of the contents and compositions of essential oils compounds during drying procedure, especially a decrease in monoterpenes and alcohols and an increase in sesquiterpenes with relatively weak volatility.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1522-1528
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• 2004

Electron spin resonance (ESR) and hydrocarbon characteristics were analyzed to establish identification conditions for irradiated dried red pepper. The ESR spectroscopy for 4 different parts (powder, pericarp, seed, stem) of the samples showed that irradiated samples signaled (g=2.024, 2.006, 1.987) a pair of peaks from a cellulose radical at intervals of 6 mT, which were not found on the non-irradiated samples. The ESR signals increased in directly proportion to the irradiation doses, which were still detectable after 12 weeks of storage at room temperature. The GC-MS analysis of hydrocarbons after fat extraction and separation by florisil column chromatography revealed that hydrocarbons, such as 1-tetradecene (14:1), 1,7,10-hexadecatriene (16:3), 1,7-hexadecadiene (16:2), 1-hexadecene (16:1), 6,9-heptadecadiene (17:2), and 8-heptadecene (17:1), were detected only from the irradiated samples immediately after irradiation and 8 months of storage. They linearly increased with the dose of irradiation, suggesting them as radiation-induced markers for irradiated dried red pepper.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.970-975
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• 2009

The residual amount of 160 kinds of pesticide for multi-analysis methods were analyzed in Baechu cabbages throughout the year by GC/MS. We investigated the 160 kinds of pesticide residues in commercial Baechu cabbages monthly from October 2007 to September 2008. Over the 12 months, the residues were detected in the Baechu cabbages harvested and distributed only in July, August, October and November. The residual amounts were 0.01 ppm Bifenthrin, 0.04 ppm Chlorfenapyr, and 0.03 ppm Bifenthrin in July, October, and November, respectively, and 0.01 2 ppm Bifenthrin in August. All residues were below MRL. These results indicate that the commercial Baechu cabbages are comparatively safe from pesticide residues.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.300-308
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• 2000

The degradation of herbicide $^{14}C-bifenox$ was studied in soils under anaerobic conditions. $^{14}C-bifenox$ was treated in silty loam and sandy loam soils, respectively at a rate of 2.1 mg/kg, and the soil was incubated under anaerobic conditions at $25^{\circ}C$ for 180 days. The mineralization, solvent extractable and non-extractable residues, degradation products of bifenox were investigated during the experiments. The relative amounts of $^{14}CO_2$ were 1.97 and 0.9% of applied $^{14}C$ in silty loam and sandy loam soils, respectively. The non-extractable residues of sandy loam soil increased dramatically up to 79.12% of applied $^{14}C$, and were higher than those of silt loam soil, suggesting physico-chemical properties and especially organic matter contributed to the difference of $^{14}C$ between two soils. The non-extractable residues were formed mainly humin fraction and increased with time. The major metabolites were nitrofen, 5-(2,4-dichlorophenoxy)-2-Nitrobenzoate, 2,4-dichlorophenoxy aniline and methyl 5-(2,4-dichlorophenoxy) anthranilate by GC/MS analysis. From the results of volatilization, mineralization and degradation of bifenox, bifenox was stable chemically and biologically in soil.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.5
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• pp.490-498
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• 2010

HCFC-22 (chlorodifluoromethane, $CHClF_2$), one of the major components in various refrigeration, is emitted mostly from developing countries, as its consumption is not limited until 2013 by the Montreal Protocol. In addition, HFC-23 (trifluoromethane, $CHF_3$), a by-product in the manufacture of HCFC-22, is also a powerful greenhouse gas. Here, we discuss the regional emission characteristics of these compounds based on high-frequency in-situ measurements using the "Medusa" GC-MS system. HCFC-22 and HFC-23 baseline concentrations measured at Gosan (Jeju Island, Korea) from November 2007 to December 2008 increased by 1.8 ppt/yr and 0.6 ppt/yr, respectively. Pollution events of these compounds were observed, very frequently (e.g., ~2~3 times) at Gosan than baseline levels. All the measurement data were divided into four groups by simultaneously considering the ratio (HFC-23/HCFC-22) and concentration (HCFC-22) at Trinidad Head (TH, California, USA). The residence time of trajectories were then analyzed in each of the four groups. The results exhibited the existence of a strong correlation with air mass origin for each group: 1) Air masses originating from Siberia in the north and from the Pacific in the south had ratios of 0.08~0.12 and concentrations of 196.9~254.3 ppt which is highly comparable to background air at TH. 2) Air masses passing over the Southern China exhibited similar ratios but higher HCFC-22 concentrations. 3) Air masses passing over the Northern China had ratios of 0.12~0.21. 4) Air masses passing over Korea and/or Japan had ratios of 0.01~0.08. Our results suggest that the HFC-23/HCFC-22 ratio can be used as a good indicator for the assessment of the pollution with Chinese origin. We also confirmed differences in air masses traveling over Northern and Southern China, most likely due to differences in air mass travelling speed over these regions before arriving at Gosan. This signature may be treated as one of the critical components in identifying the emission sources from different parts of China.

• The Plant Pathology Journal
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• v.33 no.5
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• pp.499-507
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• 2017

In an attempt to develop a biological control agent against mycotoxigenic Fusarium species, we isolated Bacillus amyloliquefaciens strain DA12 from soil and explored its antimicrobial activities. DA12 was active against the growth of mycotoxigenic F. asiaticum, F. graminearum, F. proliferatum, and F. verticillioides both in vitro and in planta (maize). Further screening using dual culture extended the activity range of strain DA12 against other fungal pathogens including Botrytis cinerea, Colletotrichum coccodes, Endothia parasitica, Fusarium oxysporum, Raffaelea quercus-mongolicae, and Rhizoctonia solani. The butanol extract of the culture filtrate of B. amyloliquefaciens DA12 highly inhibited the germination of F. graminearum macroconidia with inhibition rate 83% at a concentration of $31.3{\mu}g/ml$ and 100% at a concentration of $250{\mu}g/ml$. The antifungal metabolite from the butanol extract was identified as iturin A by thin layer chromatography-bioautography. In addition, volatile organic compounds produced by DA12 were able to inhibit mycelial growth of various phytopathogenic fungi. The volatile compounds were identified as 2-heptanone, 5-methyl heptanone and 6-methyl heptanone by gas chromatography-mass spectrometry (GC-MS) analysis. These results indicate that the antagonistic activity of Bacillus amyloliquefaciens DA12 was attributable to iturin A and volatile heptanones, and the strain could be used as a biocontrol agent to reduce the development of Fusarium diseases and mycotoxin contamination of crops.

• The Korean Journal of Mycology
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• v.32 no.1
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• pp.16-22
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• 2004

The gibberellins (GAs) play important roles in plant growth and development. Twenty three fungi were isolated from the roots of Lindera obtusiloba and Vaccinium koreanum. The numbers of GA-producing fungi were six strains from Lindera obtusiloba and four strains from Vaccinium koreanum. The fungi with GAs-producing activity were incubated for seven days in 40 ml of Czapek's liquid medium at $25^{\circ}C$, 120 rpm, and the amount of each GA in the medium was measured by gas chromatography-mass spectrometer (GC-MS) to determine the productivity of GAs. Penicillium griseofulvum KNU5379 produced more GA in case of $GA_{3}$ than Neurospora crassa known as a GAs-producing fungus. P. griseofulvum KNU5379 was shown to produce $GA_1\;9.79\;ng,\;GA_3\;133.58\;ng,\;GA_4\;2.64\;ng,\;GA_7\;7.80\;ng\;and\;GA_{53}\;0.73\;ng$ in 25 ml of liquid medium. Bioassay using culture fluid of GAs-production fungi was performed on rice sprout.

• The Korea Journal of Herbology
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• v.25 no.4
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• pp.55-59
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• 2010

Objective : This study was conducted to investigate the antioxidant activity and inhibitory effect on oxidative DNA damage of Nelumbinis Semen Extracts Methods : Nelumbins semen were extracted with hot-water and ethylacetate (EtOAC). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging assay and $Fe^{2+}$ chelating assay were performed for antioxidative effect and ${\phi}X$-174 RF I DNA cleavage assay and intracellular DNA damage assay were used for inhibitory effect on intracellular DNA damage. Results : In DPPH, Hydroxyl radical scavenging activity and $Fe^{2+}$ chelating activity of EtOAC extracts were 96.22%, 53.53%, 64.72%, while those of hot-water extracts were 20.86%, 10.72%, 29.74% at $200{\mu}g/m{\ell}$, respectively. In ${\phi}X$-174 RF I plasmid DNA cleavage assay, the protective effects of EtOAC and hot-water extracts against oxidative DNA damage were 76% and 6% at $200{\mu}g/m{\ell}$, respectively. Conclusion : These results indicated that the seed extracts of Nelumbo nucifera can be used as a natural antioxidants, which effectively inhibits the oxidative DNA damage.

• Korean Journal of Environmental Agriculture
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• v.14 no.3
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• pp.319-328
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• 1995

This study was carried out to investigate the resistance mechanism by three different kinds of procymidone-resistant and susceptible isolates of Botrytis cinerea which had been collected from green houses. The average resistance level of the resistant strains was 1,000 times higher than that of susceptible ones. Also, it was revealed that the resistance was not originated from components excreted by Botrytis cinerea, based on the result obtained from the treatment with piperonyl butoxide and triphenyl phosphate as an inhibitor of monooxygenase and esterase, respectively. The total lipod content of resistant strains was 1.3 times higher than that of susceptible ones, among fatty acids, palmitic acid, stearic acid, and linoleic and being 3.0, 2.5, and 2.0 times higher, respectinely. Also slight differences in sterol contents and components were observed. The crude chitin content was slightly higher in susceptible strains but contents of N-acetyl glucosamine, a hydrolysate of chitin, were about 2 times higher in resistant ones.