• Korean Journal of Plant Taxonomy
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• v.42 no.2
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• pp.150-156
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• 2012

While preparing a floristic study of Korean hepatics, we discovered the six unrecorded species of Lejeuneaceae from Mt. Seolak, Mt. Gaya, Geojedo, Wando and Gageodo. Archilejeunea kiushiana, Drepanolejeunea angustifolia, Lejeunea aquatica, Lejeunea otiana, Leucolejeunea japonica, and Spruceanthus semirepandus, are reported here. A. kiushiana was characterized by unlobed underleaves, homogeneous oil-bodies, and four to six perianth-keels. D. angustifolia is similar to D. ternatensis, but it differs in the dorsal margin of the leaf-lobe, which is entire or denticulate, spines never present, and leaf cells smooth or with minute dorsal bulging. L. aquatica is similar to L. japonica in that it has a wider and similar shape (wider than long) of its underleaves and has homogeneous oil-bodies. The former, however, has minute leaf-lobules (5-15 cells), 1/10 to 1/5 the length of the leaf-lobe, versus leaf-lobules 1/4 to 1/3 the length of the leaf-lobe. L. otiana is similar to L. kodamae in that it has a large and acute first tooth of the leaf-lobule but differs in having plain leaf-lobules obliquely quadrate and an indistinct second tooth. Drepanolejeunea (Spruce) Schiffn. is widely distributed in tropical and subtropical regions (Mizutani, 1961). L. japonica is characterized by entire underleaves; one large, coarsely segmented oil-body per leaf cell; and a large second tooth of the leaf lobule, two to six cells long, and two to three cells wide at the base. S. semirepandus is widely distributed in tropical and subtropical regions in Asia. This species is characterized by small homogeneous and numerous oil-bodies, up to 10 smooth perianthkeels, and leaf-lobe acute at the apex.

• Korean Journal of Medicinal Crop Science
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• v.12 no.2
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• pp.149-153
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• 2004

This study was carried out to compare the major volatile components in essential oil from different origin of Atractylodes spp. which is being traded as a crude herbal drug in Korean herbal markets. From the two Atractylodes of major volatile components were similarly detected such as the ${\beta}-selinene,\;{\beta}-sesquiphellandrene$, germacrene B, 2,7-dimethoxy-2-methylnaphthalene and 9-methoxy-2,3-dihydrofuro{3,2-q}coumarin. Among the volatile components, the major components were 2,7-dimethoxy-2-methylnaphthalene (40.98%), 9-methoxy-2,3-dihydrofuro {3,2-q} coumarin (15.74%), and ${\beta}-sesquiphellandrene$ (1.98%) in both Atractylodes. As a results, It was found that the two Atractylodes were the same species which was being traded in the Korean herbal markets as the A. japonica. not to different species of A. japonica and A. macrocephalla, respectively.

• Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.132-137
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• 2005

Olive flounder (Paralichthys olivaceus) is one of the most commercially important species of farmed marine fish in Korea. Although techniques for rearing the larva of this species are improving, production costs are also increasing due to microbial influences and genetic degradation caused by successive culturing. Since the demand for healthy seed, which requires eggs of good quality of, is high, we examined the effects of nutrient composition on the size of P. olivaceus eggs. We analyzed floating (live) and sunken (dead) eggs of P. olivaceus from five different hatcheries for their size and amino and fatty acid composition. The sizes of eggs and oil globules from floating vs. sunken eggs were significantly different at p<0.05. No significant relationships were observed, however, among larval length, hatching percentage, and egg and oil globule size. The dry weight and amino acid levels of floating eggs were greater than those of sunken eggs (p<0.05), but no difference in fatty acid content was observed.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.37-44
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• 2013

Generally, a reduced chemical mechanism of n-heptane is used as chemical fuel of a 3-D diesel engine simulation because diesel fuel consists of hundreds of chemical components and various chemical classes so that it is very complex and large to use for the calculation. However, the importance of fuel in a 3-D simulation increases because detailed fuel characteristics are the key factor in the recent engine research such as homogeneous charged compression ignition engine. In this study, normal paraffin, iso paraffin and aromatics were selected to represent diesel characteristics and n-dodecane was used as a representative normal paraffin to describe the heavy molecular weight of diesel oil (C10~C20). Reduced kinetics of iso-octane and toluene which are representative species of iso paraffin and aromatics respectively were developed in the previous study. Some species were selected based on the sensitivity analysis and a mechanism was developed based on the general oxidation scheme. The ignition delay times, maximum pressure and temperature of the new reduced n-dodecane chemical mechanisms were well matched to the detailed mechanism data.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.3 s.52
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• pp.265-271
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• 2005

This study is performed to investigate the effects of citrus essential oils on melanin production in B16 melanoma cells and reactive oxygen species (ROS) generation in RBL 2H3 cells. Five kinds of citrus essential oil (bergamot, grapefruit, lemmon, mandarin, petigrain) did not have any influence on DPPH radical scavenger activity, cell growth and cytotoxicity in B16 melanoma cells. In purified tyrosinase assay, both mandarin and petigrain essential oils dose-dependently inhibited its activity, but bergamot did not. In $1{\mu}M\;{\alpha}-MSH-stimulated$ B16 melanoma cells, all of 5 citrus essential oils inhibited melanin production in $\underline{a}$ dose dependent manner. On the other hand, four kinds of citrus essential oil dose-dependently increased ROS generation in RBL 2H3 mast cells, but mandarin did not. From the above results, it is possible that citrus essential oils nay be developed to be anti-melanogenic agent on the basis of their inhibitory effect on MSH-induced melanin production. Hut we can not rule out the possibility of the induction of allergy and inflammation since citrus essential oils caused ROS generation in RBL 2H3 mast cells.

• Korean Journal of Plant Taxonomy
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• v.50 no.2
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• pp.227-231
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• 2020

While conducting a floristic study of Korean hepatics, we discovered two unrecorded species, which were collected from wind holes near the Donggang River, Korea. Mannia fragrans (Balb.) Frye & L. Clark and Mannia androgyna (L.) A. Evans are hereby reported for the first time in Korea. M. androgyna is characterized by pale grayish oil bodies in both the aerenchyma and basal tissue, and saccate spores with a conspicuous proximal disc. M. fragrans is characterized by a gynoecial segment with a whitish apical brush of scales, a commonly aromatic smell, and areolate spores with a conspicuous proximal disc. Two unrecorded species are described and illustrated based on Korean material.

• Journal of Microbiology and Biotechnology
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• v.19 no.4
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• pp.391-396
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• 2009

The chemical compositions, and antibacterial and antifungal effects of essential oils extracted from three coniferous species, Pinus densiflora, Cryptomeria japonica, and Chamaecyparis obtusa, were investigated. Gas chromatography mass analysis of the essential oils revealed that the major components and the percentage of each essential oil were 16.66% $\beta$-phellandrene and 14.85% $\alpha$-pinene in P. densiflora; 31.45% kaur-16-ene and 11.06% sabinene in C. japonica; and 18.75% bicyclo [2,2,1] heptan-2-ol and 17.41% 2-carene in Ch. obtusa. The antimicrobial assay by agar disc diffusion method showed that $2.2{\mu}g$ of Ch. obtusa oil inhibited most effectively the growth of Escherichia coli ATCC 33312 and Klebsiella oxytoca ATCC 10031, whereas the C. japonica oil gave weak antimicrobial activity. The minimal inhibitory concentration(MIC) values for bacterial strains were in the range of 5.45-21.8 mg/ml depending on essential oils, but most Gram-negative bacteria were resistant even at 21.8 mg oil/ml. P. densiflora oil showed the most effective antifungal activity and the MIC values for Cryptococcus neoformans B42419 and Candida glabrata YFCC 062CCM 11658 were as low as 0.545 and 2.18 mg/ml, respectively. Cryp. neoformans B42419 was the most sensitive to all essential oils in the range of 0.545-2.18 mg/ml. Our data clearly showed that the essential oils from the three conifers had effective antimicrobial activity, especially against fungi.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.537-541
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• 2004

Based on reaction time and substrate molar ratio, structured lipid (SL-corn) was produced at 1:2:2(corn oil/capric acid/CLA) and 4% immobilized lipase from Rhizomucor miehei (RM IM). Reaction was carried out for 24 hr at $55^{\circ}C$ in 1-L stirred-batch reactor. After reaction, 13.3 mol% capric acid and 8.9%, CLA were incorporated into corn oil. Iodine and saponification values of SL-corn were 68 and 202, respectively. Tocopherol content decreased after reaction (about 39%). SL-corn showed more yellowish color than corn oil (p<0.05). Reversed-phase HPLC indicated triacylglycerol species containing capric acid in SL-corn resulted in faster crystallization than that of corn oil.

• Korean journal of food and cookery science
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• v.33 no.3
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• pp.256-263
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• 2017

Purpose: Essential oils are secondary metabolites of herbs and have antibacterial activities against foodborne pathogens. However, their applications for food protection are limited due to the hydrophobic and volatile natures of essential oils. Methods: In this study, essential oil nanoemulsions of rosemary and lavender were formulated with non-ionic surfactant Tween 80 and water using ultrasonic emulsification, and their antibacterial effects were determined. Results: The antibacterial activities of nanoemulsions were evaluated against 12 strains of 10 bacterial species, and significant antibacterial effects were observed against four Gram-positive and four Gram-negative bacteria but not against Streptococcus mutans and Shigella sonnei. In the disc diffusion test, the diameter of the inhibition zone proportionally increased with the concentration of nanoemulsions. Using cell turbidity measurement, minimum bactericidal concentration (MBC) of the nanoemulsions, which is the lowest concentration reducing viability of the initial bacterial inoculum by ${\geq}99.9%$, was significantly higher than the minimum inhibitory concentration (MIC) of the nanoemulsions. The largest bactericidal effects of lavender and rosemary essential oil nanoemulsions were observed against S. enterica and S. aureus, respectively. Conclusion: Nanoemulsion technique could improve antibacterial activity of essential oil nanoemulsions by increasing the solubility and stability of essential oils. Our findings shed light on the potential use of essential oil nanoemulsions as an alternative to chemical sanitizers in food protection.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.210-215
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• 2018

Objectives: The main objectives of this study were to verify the antibacterial activity of two essential oils, lavender and peppermint, against dental caries and to review their synergistic effect when used in combination. Our results provide basic data for the evaluation of the use of these two substances towards the prevention and cure of dental caries. Methods: The sample solutions of lavender and peppermint oils were prepared in three different concentrations (30%, 50%, and 70% (v/v)) by diluting them with third-distilled water and Tween 20. Streptococcus mutans was selected as the bacterial species for testing. The disk diffusion method was used to measure the antibacterial activity of the sample solutions. For generating growth curves and measuring the number of clusters of the bacterial, the liquid medium-dilution method was used; the absorbance of the medium was measured at 600 nm after 3, 6, 12 and 24 hours. Results: When the antibacterial activity of the oils was tested via the disk diffusion method, the activity improved with increasing concentrations of all the sample solutions of peppermint, lavender, and the blend, but there was no significant difference between them with respect to the type of oil. In the growth curves of S. mutans, growth inhibition was observed after 12 hours. The inhibitory effect of 30% lavender oil on growth was 64.9% and 80.1% after 12 and 24 hours of treatment, respectively whereas that of peppermint oil was 71.3% and 80.1% after 12 and 24 hours of treatment, respectively. The inhibitory effect of the blended oil was 71.9% and 81.0% after 12 and 24 hours of treatment, respectively. Conclusions: Further research is still required in order to determine the efficacy of lavender and peppermint oils, as well as other essential oils, for wider use in preventing dental caries.