• Archives of Pharmacal Research
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• v.27 no.1
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• pp.44-47
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• 2004

Loranthus tanakae Fr. et Sav. (Loranthaceae) is a species of mistletoe, a semiparasitic plant growing on the branches of Quercus and Betula species as host trees. In our ongoing search for bioactive compounds from endemic species in Korea, we have investigated to isolate the chemical constituents responsible for the antitumor effect of the MeOH extract of L. tanakae. The ethyl acetate soluble part of the MeOH extract demonstrated a marginal inhibition on the proliferation of the tumor cell lines such as A549 (non small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nerve system), and HCT-15 (colon) in vitro. Thus, the activity-guided isolation procedure upon the ethyl acetate soluble part of the extract has been carried out and finally four flavonoid rhamnopyranosides (1-4) were isolated as active principle. The structures of 1-4 were elucidated by the physicochemical and spectral data as rhamnetin 3-O-$\alpha$-L-rhamnoside (1), quercetin 3-O-$\alpha$-L-rhamnoside (2), rhamnocitrin 3-O-$\alpha$rhamnoside (3), and kaempferol 3-O-$\alpha$-L-rhamnoside (4).

• Journal of the Korean Wood Science and Technology
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• v.31 no.1
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• pp.16-21
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• 2003

The methanol extractives from root bark of Ulmus davidiana var japonica nakai were fractionated with n-hexane, ethyl ether, ethyl acetate and waster, the water soluble fraction was also fractionated with silicagel column chromatograhy. The chemical structure of purifided compounds were identified with UV, IR, ¹H-NMR and ¹³C-NMR spectra and the antibacterial activities also were investigated. Two different antibacterial compounds (compound A and B) were fractionated with silicagel chromatography and TLC. Compounds B was identified as a catechin rahmnoside. The both of compounds had antibacterial activity on Staphylococcus aureus and Salmonella typhimurium.

• Mycobiology
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• v.40 no.2
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• pp.100-106
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• 2012

Interest in commercial cultivation and product development of Cordyceps species has shown a recent increase. Due to its biochemical and pharmacological effects, Cordyceps militaris, commonly known as orange caterpillar fungus, is being investigated with great interest. Cultivation of C. militaris has been practiced on a large scale in order to fulfill a demand for scientific investigation and product development. Isolates of C. militaris can be easily established from both spores and tissue. For isolation of spores, ascospores released from mature stromata are trapped in sterile medium. Multi-ascospore isolates, as well as combinations of single ascospore strains, are used for production of fruiting bodies. Progeny ascospore strains can be isolated from artificial fruiting bodies, thus, the cycle of fruiting body production can be continued for a long period of time. In this study, we examined fruiting body production from multi-ascospore isolates and their progeny strains for three generations. $F_1$ progeny strains generally produced a larger number of fruiting bodies, compared with their mother multi-ascospore isolates; however, $F_2$ and $F_3$ progeny strains produced fewer fruiting bodies. Optimum preservation conditions could help to increase the vitality of the progeny strains. In order to retain the fruiting ability of the strains, further testing of various methods of preservation and different methods for isolation should be performed.

• Journal of the Korean Society of Safety
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• v.35 no.2
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• pp.84-93
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• 2020

In recent years, the scale of damage from disasters such as earthquakes and large-scale fires and floods that are occurring in Korea is increasing. Accordingly, interest in urban disaster prevention that combines living infrastructure such as roads and parks is boosting, and it is urgent to prepare measures to reduce the damage scale of local cities. The purpose of this study is to derive implications for disaster prevention measures in areas where disaster prevention safety of local cities is weak through examples of disaster prevention safety of local cities in case of disaster. To this end, this study analyzed the regional characteristics, current status, and disaster prevention problems of regional cities in Japan, and selected disaster-vulnerable areas, and considered the distance relationship between disaster prevention bases through road network analysis. In addition, road closure simulation using ArcGIS Network Analyst was conducted to analyze disaster prevention safety in the area. As a result, the situation of the village which has a high possibility of isolation by natural disasters was grasped in advance. Through this, the suburbs confirmed the necessity of supplementing the disaster prevention function through transportation maintenance such as forest roads, and it was found that the city needs to prepare a risk management system. Furthermore, this study suggests the need for research on areas with a high possibility of isolation, especially in areas where disaster prevention functions are weak in local cities in case of disaster, and shows countermeasures for disaster prevention measures and resident education.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.288-291
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• 2012

Korean oak wilt disease caused by Raffaelea quercus-mongolicae is vectored by the ambrosia beetle Platypus koryoensis. To prevent the spread of the disease, the beetle infested oak tree had been cut into logs, covered with plastic vinyl, fumigated with a pesticide, and stored for three years on the site where the tree was cut. This study was carried out to get information on the fungi colonizing the fumigated oak wood. Wood disk samples collected from the fumigated oak logs at two locations in the Taejo Mountain, Cheonan city, were used for fungal isolation. A total of 99 filamentous fungal isolates were obtained from the wood disk samples. Hypocrea spp., Trichoderma spp. and Penicillium spp. were identified based on morphological characteristics and nucleotide sequence analysis of translation elongation factor 1-alpha gene and ITS rDNA region. Trichoderma was the major fungal group. R. quercus-mongolicae, and P. koryoensis were not detected from the fumigated oak wood. Our work provided evidence that after three years of storage, the fumigated oak wilt-diseased logs should be no longer harmful source of oak wilt disease transmission.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.93-103
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• 2015

The isolation, cloning, and characterization of an R2R3-MYB transcription factor gene (MtMYB70) from the model legume Medicago truncatula is reported. MtMYB70 consists of a 768-bp coding sequence corresponding to 255 amino acids. Sequence alignment revealed that MtMYB70 cDNA contains conserved R2R3-type MYB domains with highly divergent C terminal regions. MtMYB70 was found to have relatively low sequence homology with known R2R3-MYB genes. Phylogenetic analysis placed the R2R3-MYB domain of MtMYB70 closest to PtMYB1, a known activator of lignin biosynthesis. Overexpression of MtMYB70 under the control of the 35S promoter in transgenic poplar did not cause a significant difference in total lignin content relative to the control, but glucan content was significantly increased in transgenic poplar. Therefore, MtMYB70 might have regulatory role in the biosynthesis of cell wall structural carbohydrates.

• The Korean Journal of Ecology
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• v.15 no.2
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• pp.181-189
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• 1992

Dictyostelid cellular slime molds were quantitatibly isolated from the soils of mt.halla (above 900m in altitude), korea, according to the 'clonal isolation technique(cavender and raper, 1965a)'. Total fifteen species were found, including 1 new and 6 undescribed species.these are dictyostelium mucorodes, dictostelium minutem,polysphondylium pallidum fasciculatum, polysphondylium violaceum, dictyostelium flavidum,dictyostelium fasciculatum, polysphondylium violaceum, dictyostelium flavidum sp. n.(HL-1),dictyostelium aureo-stipes var. aureo-stipes, dictyostelium capitatum, dictyostelium giganteum,dictyostelium polycephalum,dictyostelium brefeldianum,dictyostelium macrocephalum, and dictyostelium sphaerocephalum, dictyostelium sp. (HL-2), dictyostelium sp. (CJ-9). D. mucoroides was the dominant species, and D. minutam,p.pallidum, d. fasciculatum, and p. violaceum were relatively common. d. polycephalum, d. brefeldianum, d. macrocephalum, dictyostelium sp. (HL-3), and d. sphaerocephalum were very rare. Species diversity appeared to be the highest in the deciduous broad-leaved forest from the soils of which 14 species were isolated. eight species were, including five undescribed species, isolated only from this forest soils. Number of isolates severely decrease at the forests above 1,500m in altitude.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.150-156
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• 2020

Weeds play an important role in the survival of viruses and are potential inoculum sources of viral diseases for crop plants. In this study, specimens of Pseudostellaria heterophylla exhibiting symptoms of the cucumber mosaic virus (CMV) were collected in Bonghwa, Korea. The characteristics of the disease were described and leaf RNA was extracted and sequenced to identify the virus. Three CMV contigs were obtained and PCR was performed using specific primer pairs. RNA from positive samples exhibiting CMV leaf symptoms was amplified to determine the coat protein. A sequence comparison of the coat protein gene from the CMV BH isolate shared the highest nucleotide identity (99.2%) with the CMV ZM isolate. Phylogenetic analysis showed that CMV-BH belonged to subgroup IA and that the most closely-related isolate was CMV-ZM. All test plants used for the biological assay were successfully infected with CMV and exhibited CMV disease symptoms such as blistering, mosaic, and vein yellowing. To our knowledge, this is the first report of CMV infection in P. heterophylla from Korea.

• Journal of the Korean Wood Science and Technology
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• v.38 no.5
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• pp.444-449
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• 2010

Ulmus davidiana var. japonica is a deciduous tree used in traditional medicine. In this study, we examined the antioxidant and anti-inflammatory activity of extracts and compounds isolated from U. davidiana var. japonica stem barks for development of cosmetic phyto-materials. Phytochemical examination of the stem bark led to the isolation and characterization of three known compounds, (+)-catechin (1), (+)-catechin-7-O-${\beta}$-D-apiofuranoside (2), and procyanidin B3 ((+)-catechin-($4{\alpha}{\to}8$)-(+)-catechin) (3). Their bioactivities including antioxidant (DPPH ree radical scavenging assay) activity, anti-inflammatory (nitric oxide nhibition assay) were evaluated. Most of the crude extracts and isolates indicated significant antioxidant potential compared with BHT and ${\alpha}$-tocopherol as controls. Futhermore, all compounds showed higher inhibitory activities for NO production in Raw 264.7 cells than the L-NMMA using the positive control. Eespecially, (+)-catechin (1) and (+)-catechin-7-O-${\beta}$-D-apiofuranoside (2) which could inhibit more than 90% of the NO production at a concentration of 100 ${\mu}g/m{\ell}$, implying excellent anti-inflammatory activity.

• Korean Journal of Microbiology
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• v.25 no.3
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• pp.238-243
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• 1987

In this study, an acidoduric Streptomyces strain was isolated and identified from acidic forest soil around Dankook University, Cheonan Campus. This isolated strain had rod-shaped, smooth, non-motile spore and the shape of spore chain was compact spiral. This structure appeared similar to the sporangium of the genus Streptosporangium but this strain proved to be a Streptomyces strain by an electron microscopic study and cell wall analysis. This strain showed a best growth on neutral medium, was also able to grow on the acidic media of pH 4.0 and pH 5.0. The color determination of this strain on various agar media and other physiological tests were carried out by ISP-methods. From these results, the isolated strain was considered to be Streptomyces mirabilis.