• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.364-370
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• 2003

Essential oil of Thuja occidental leaves was extracted by steam distillation method, and chemical composition of essential oil was analyzed by GC-MS. The essential oil was tested to antimicrorbiaI activity against 28 test microorganisms and antioxident assay through DPPH free radical scaveging test and insecticidal activity by mosquito insecticide assay. The major constituents in the essential oil of T. occidental were monoterpene as d-isothujone, ${\alpha}-thujone$, camphor, L-fenchone, and hornyl acetate. The essential oil have broad antimicrobiaI activity, which showed strong antimicrobiaI activity for Streptococcus pyogenes as bacteria, Alternaria alternata, Aspergillus niger, Aspergillus oryzae, Saccharomyces cerevisiae, and Streptococcus mutans as fungi. The essential oil also showed DPPH free radical scavenging ability at concentration of $36\;{\mu}{\ell}/m{\ell}$. In spraying and fumigation tests, the essential oil had strong insecticidal activity against mosquito.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.208-215
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• 2016

Vaccinium oldhamii Miq. is a Korean native tree, which is deciduous and shrub tree with broad leaf. Fruits were used primarily for edible or medicinal purposes for bladder infection in Korea and China. However, there is a lack of information on the degree of variation of phytochemical contents and antioxidant activity of these native clonal. We investigated morphological characteristics, phytochemical contents (polyphenol, flavonoid, anthocyanin) and antioxidant activity for the fruits of 24 individual variation from 4 different regions in Korea. The results in terms of horticultural traits and biochemical characteristics showed significant differences among populations and among individuals within population. The total phenolic contents ranged from 4.40 to 10.58 mg GAE/g and the total flavonoid contents ranged from 2.02 to 8.09 mg NE/g. The total anthocyanin contents ranged from 232.5 to 684.3 mg CGE/100g. Reducing power fruits ranged from 0.15 to 1.43 and DPPH free radical scavenging activity ranged from 49.1 to 97.5% at 400 ppm. Results revealed that the region of origin greatly influenced the phytochemical contents and antioxidant activity of V. oldhamii, which might help for the selection and validation of the most productive cultivars in the food and pharmaceutical industries.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.533-542
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• 2014

We extracted essential oils from four species (Pinus densiflora, Larix kaempferi, Pinus koraiensis, and Abies holophylla) in the family Pinaceae to investigate their antibacterial activities against respiratory tract bacteria (Klebsiella pneumoniae, Haemophillus influenzae, Streptococcus pyogenes, Streptococcus pneumonia, and Neisseria meningitides). Among the tested oils, that from A. holophylla was showed strong activity based on disc diffusion and broth medium dilution (minimum inhibitory concentration, MIC) assays. Qualitative analysis of A. holophylla oil was carried out by GC-MS; ${\alpha}$-pinene, camphene, ${\beta}$-pinene, 3-carene, limonene, bornyl acetate, borneol, ${\beta}$-caryophyllene, ${\alpha}$-caryophyllene, caryophyllene oxide, and ${\alpha}$-bisabolol were identified as its major constituents. Fractionation by silica gel chromatography was performed to analyze the active constituents of the crude oil. In particular, one fraction containing caryophyllene oxide as the major constituent showed stronger antibacterial activity than the crude oil of A. holophylla. Growth rates of bacterial strains exposed to fraction D were explored by optical density (OD600) measurements while morphology was examined by optical microscopy observations ( ${\times}1000$). OD600 of K. pneumoniae decreased from 0.2582 to 0.005 in response to treatment with fraction D at a MIC value of $0.31{\mu}{\ell}/m{\ell}$.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.14-20
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• 2007

In order to examine the differences in antioxidant enzyme activities which represent defence mechanism to stressful environments, and soil properties between healthy and declining (or unhealthy) trees, we selected three sites, Witseorum, Youngsil and Sungpanak (Jindallebat). Antioxidant enzymes including Ascorbate peroxidase (APX) and Glutathione Reductase (GR), forest soil properties including soil texture, soil pH, organic matter, total nitrogen, available phosphate, cation exchange capacity, exchangeable cation content and nutrient contents in leaves of Abies koreana (Korean fir) trees were analyzed. There were no significant differences between healthy and declining trees in GR activity. However, seasonal difference in antioxidant enzyme activity was observed. GR activity was lower in June and August than that of September. Soil chemical and physical properties of each site showed a tendency that organic content, total nitrogen content, available phosphorus, cation exchange capacity and cation content were lower at the site of declining trees than the site of healthy trees.

• The Korean Journal of Pesticide Science
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• v.7 no.2
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• pp.83-91
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• 2003

Methanol extracts from 207 samples of 118 plant species in 44 families were tested for their fungicidal activities against six phytopathogenic fungi. Extracts of Thuja orientalis leaf, Cinnamomum loureirii leaf, Lindera erythrocarpa barks and leaf, Pinus koraiensis wood, Hovenia dulcis wood, Koelreuteria paniculata barks, Styrax japonica wood, Camelia japonica leaf and Cleyera japonica leaf showed very strong fungicidal activity against more than two phytopathogenic fungi at a concentration of 2000 ppm. As a naturally occurring fungicide, these plants could be useful as new fungicidal products against various plant diseases induced by plant pathogens.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.397-402
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• 2015

This study was carried out to analyze the nutritional composition, bioactive compound and antioxidant activity in fresh sprout of 3 new Kalopanax septemlobus cultivars. Cheong-San, Cheong-Song and Cheong Sun 1 had largest carbohydrate (52.90, 53.12, 55.28%), crude protein (34.23, 31.33, 33.58%) in the proximate composition and had largest K (2.29, 2.22, 2.23%) followed by Ca (0.44, 0.34, 0.37%), Mg (0.24, 0.19, 0.19%) in the mineral contents. Three new cultivars contained a total of 26, 25 and 28 different kinds of amino acids, respectively and the number of essential amino acid is 6, 6 and 7 species, respectively. Also, Cheong-San had higher total polyphenol contents and Cheong-Song had higher total flavonoid contents. DPPH free radical scavenging activity of 70% ethanol, water extracts of Cheong-San and Cheong-Song is higher than others at 100 ppm. In the ABTS radical cation decolorization activity, 70% ethanol extract of Cheong Sun 1, water extract of Cheong-San and Cheong-Song are higher activity than others and all samples have more than 85% ABTS racial cation decolorization activity at 500 ppm. Our results suggest that new K. septemlobus cultivars possess good antioxidant capacities with a high nutritional value and might have potential applications in the food and medical industries.

• Journal of Korea Foresty Energy
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• v.24 no.2
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• pp.24-30
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• 2005

Four compounds, (+)-catechin (1), (-)-epicatechin (2), myricitrin (3), and hinokiflavone (4), were isolated from the needles of Juniperus occidentalis Hook. The structures of the isolated compounds were established by NMR and MS spectrometer. The antioxidant activity of the isolated compounds was determined by measuring free radical scavenging activity with DPPH and the results indicated that compound 1, 2, and 3 showed better activity than the controls, while compound 4 had weak activity compared with ${\alpha}-tocopherol$, BHT, and curcumin.

• Journal of Forest and Environmental Science
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• v.28 no.1
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• pp.19-23
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• 2012

Recently the Korean government provided forest recreation areas through developing evaluation index of rural areas amenity resources, forest therapy and recreational forest for revitalization of rural areas and national health promotion. However, what the public wants is just one place which includes all recreational facilities. GRAT tourism means Green, Rest and Therapy-Tourism. It is a new concept of recreational forests. This study defines GRAT-Tourism, the new concept of recreational activity and discusses the development of the GRAT-Tourism Evaluation Index.

• Fire Science and Engineering
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• v.24 no.1
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• pp.103-110
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• 2010

Farming activity was the second cause of forest fire following the carelessness. In this study, 74 forest fires caused by farming activity and waste burning in 2009 was investigated for analyzing ignition patterns. The main cause to bring about forest fire was the farming waste burning as 25 cases, burning of farming waste matter after product and household waste burning were the second causes as 19 cases. Landcovers which transfer flame from ignition point to forest were fallow field graveyard, field fruit farm, field levee fallow field. The average distance between ignition point and forest sleeve was 19 m, and the maximum distance was 130 m. The probability of forest fire ignition was high in the 100 m buffer zone from the forest sleeve that is the prohibition rule of fire use for forest fire prevention at the forest fire season.

• Journal of Forest and Environmental Science
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• v.37 no.3
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• pp.226-234
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• 2021

Two species, P. pyrifolia and P. ussuriensis, of the genus Pyrus native to Korea, are valuable genetic resources that can be used for food, dietary supplement, pharmaceutical, and cosmetics. Bioactive compounds of the plant leaves are the main components that are used for the products. Farmers had cultivated a few individuals from the wild to produce fruits or leaves for traditional remedy or tea; however, bioactive components of their leaves are not tested. We selected some trees from the natural stand that have distinct traits for the improvement program. We investigated the bioassay on the extracts' bioactive compounds and antioxidant capacity from the selected accessions and other accessions, including newly developed cultivars. The contents of the phenolic compounds and flavonoids from the leaf extracts of the selected accessions were higher than the commonly cultivated trees in both species but lower than 'Sanhyang' in P. ussuriensis. The antioxidant capacity was measured using two assay methods, DPPH and ABST. The selected cultivars also had higher inhibitory activity than common trees. The selected accession 'Cultivar 3' in P. pyrifolia had the highest radical scavenging activity than others. Although leaves of the accessions were used only in this study, all three selected individuals have the potential for cultivar in containing high bioactive compounds and antioxidant capacity.