• Natural Product Sciences
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• v.25 no.2
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• pp.150-156
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• 2019

Conventional extraction of oil and azadirachtin, a botanical insecticide, from Azadirachta indica involves defatting the seeds and leaves using hexane followed by azadirachtin extraction with a polar solvent. In order to simplify the process while maintaining the yield we explored a binary extraction approach using Soxhlet extraction device and hexane and ethanol as non-polar and polar solvents at various ratios and extraction times. The highest oil and azadirachtin yields were obtained at 6 h extraction time using a 50:50 solvent mixture for both neem leaves (44.7 wt%, $720mg_{Aza}/kg_{leaves}$) and seeds (53.5 wt%, $1045mg_{Aza}/kg_{leaves}$), respectively.

• Natural Product Sciences
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• v.29 no.2
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• pp.113-119
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• 2023

Descurainia sophia seeds methanol extract showed significant anti-influenza activity and we tried to isolate anti-influenza compounds from the D. sophia extract. D. sophia seeds were extracted with 80% methanol and fractionated with n-hexane, ethyl acetate, CHCl₃ and n-butanol. The anti-influenza activity of each fraction was assessed using sulforhodamine B (SRB) method in A549 cells, human-derived lung cancer cells. The ethyl acetate and CHCl₃ fractions showed the most potent anti-influenza activity. Seven compounds were isolated from CHCl₃ fraction and identified 1-decanol (1), 2-(3,4-dihydroxy-2-methylenebutoxy)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol (2), daucosterol (3), isorhamnetin (4), quercetin (5), sinapic acid (6), and helveticoside (7) by spectroscopic data such as UV, IR, ¹H-NMR, ¹³C-NMR and mass spectroscopy. Anti-influenza activities of isolated compounds were evaluated using SRB method in A549 cells. Compounds 3, 4 and 7 had significant anti-influenza activity in a dose-dependent manner.

• Natural Product Sciences
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• v.25 no.4
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• pp.348-353
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• 2019

Soluble epoxide hydrolases (sEH) are enzymes present in all living organisms, metabolize epoxy fatty acids to 1,2-diols. sEH in the metabolism of polyunsaturated fatty acids plays a key role in inflammation. In addition, the endogenous lipid mediators in cardiovascular disease are also broken down to diols by the action of sEH that enhanced cardiovascular protection. In this study, sEH inhibitory guided fractionation led to the isolation of five phenolic compounds trans-resveratrol (1), trans-piceatannol (2), sulfuretin (3), (+)-balanophonin (4), and cassigarol E (5) from the ethanol extract of the seeds of Passiflora edulis Sims cultivated in Vietnam. The chemical structures of isolated compounds were determined by the interpretation of NMR spectral data, mass spectra, and comparison with data from the literature. The soluble epoxide hydrolase (sEH) inhibitory activity of isolated compounds was evaluated. Among them, trans-piceatannol (2) showed the most potent inhibitory activity on sEH with an IC₅₀ value of 3.4 μM. This study marks the first time that sulfuretin (3) was isolated from Passiflora edulis as well as (+)-balanophonin (4), and cassigarol E (5) were isolated from Passiflora genus.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.3
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• pp.35-47
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• 2004

In order to study changes in vegetation pursuant to rooftop revegetation plantation methods, plantation methods for rooftop revegetation were divided into two types through an analysis of recent trends. Then, Planted plants and invasive plants on sites where the planting methods were introduced were monitored. Planting methods were divided into mono-layer meadow cover type and multi-layer planting cover type. They showed some differences in terms of the availability of wetland, the structure of vegetation layers, the planted species, and the material of mulching. According to the results of monitoring the two sample sites for different plantation methods, the number of invasive plants was higher in multi-layer planting cover type and the ratio of naturalized plants was higher by 30% in average in mono-layer meadow cover type. The main reason for such a result is that the natural soil used in the multi-layer planting cover type likely contained some seeds. Moreover, it's harder for invasive plant seeds to germinate in volcanic rocks than in natural soil. Also, it is attributable to wetlands available in multi-layer planting cover type and diverse living environments created by multi-layer planting. The reason of the ratio of naturalized plants being higher by at least 10% in mono-layer meadow cover type is the character of naturalized plants being stronger in unfavorable conditions than nature plants are. Accordingly, the germination rate in the volcanic rock mulching has likely contributed in raising the introduction and germination of naturalized plants. The results showed that multi-layer planting cover type using wetland creation and nature soil can increase the number of invasive plants and lower the ratio of naturalized plants. However, since seeds contained in the natural soil can affect the growth of planted plants, this needs to be clarified, It was judged that mono-layer meadow cover type may affect more greatly on the germination and growth of invasive plants than on those of planted plants, Its potential adoption in highly urbanized areas was examined. By complementing with the mutual benefits of each plantation method, it appeared possible to shift to a rooftop revegetation system suitable to the site.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.144.2-145
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• 2003

This study was performed to investigate the incidence of Hosta uirus X (HVX), a Potexvirus, from cultivated hosta ornamental plants in Korea and to ascertain seed transmission of the virus from infected parent plant to progeny ones for breeding program of hosta plants. Infection rate of HVX in cultivated hostas was 25.6 ％ (11 out of 43 collected samples contained HVX) based on Western blot and RT-PCR detection methods. Most of HVX-infected hostas showed visible systemic leaf symptoms (mosaic, mottle, curling, stunting or combinations). Variability of HVX was confirmed by sequences of coat protein gene of individual isolates from different hostas. HVX was seed-transmitted on Hosta 'Blue Cadet'. The virus was detected from seeds, and sprouts and seedlings from the virus-contaminated seed sources. Over 7.5 ％ of seeds were HVX-contaminated surveyed in this study, Our data suggest that HVX can be transmitted by seed source, and indexing of the virus should be done for breeding program of Hosta.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.331-339
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• 2023

This study was conducted to identify seed inflow characteristics according to harvest typeand to provide basic data for developing a regeneration technology for secondary growth forests in Korean red pine (Pinus densiflora) succession forest formation by natural regeneration. Experimental sites were established by applying seed tree (single and group) and clear-cutting methods (10- 20- 30-m strip and 20- 30- 40-m patch). The seed inflow characteristics of the natural regeneration site were analyzed for 6 years from 2014. Most seeds were flowed to the regeneration stand from October to November. In years with good seed fructification, more than 80% were flowed in October. The average annual seed inflow by harvest type was highest in the seed tree area (296,000 seeds/ha/yr), followed by the 20-m patch clear-cutting area (291,000 seeds/ha/yr) and 10-m strip clear-cutting area (281,000 seeds/ha/yr). The distribution uniformity of seed inflow according to treatment was analyzed in the order of the 20-m strip clear-cutting area (52.2), 20-m patch clear-cutting area (52.9), and 10-m strip clear-cutting area (56.1). As a result, the 10-m strip and 20-m patch clear-cutting areas with relatively small harvest areas showed high seed inflow and distribution uniformity.

• The Korean Journal of Ecology
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• v.17 no.4
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• pp.463-469
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• 1994

For better understanding of population dynamics of Symplocarpus renifolius, some aspects of seed production were studied in natural populations for 3 years. The rate of reproducing plants (RP) was 8.06% among the whole studied. The RPs were 0.0% in leaf size class under 500cm2 per individual, and 3.6% in 500~1,000cm2, and 44.3% in over 3,000cm2. The resource allocated to sexual organ was 11.6% of total biomass at the end of growing season, and that to belowground was about 80% regradless of presence or absence of sexual organ. In the previous and the next years of seed production, the energy allocated to sexual organ didn't affect the changes of leaf size, year by year. After flowing season. Especially, a large number of sex organ were degraded in April, a period of pollination and fertilization. The number of seeds per individual was degraded in April, a period of pollination and fertilization. The number of seeds per individual was 13~22 and didn't relate to leaf size. But the weight per seed increased along leaf size per individual. Therefore, in S.renifolius population, large individual produced large seeds rather than many seeds.

• Korean Journal of Plant Resources
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• v.21 no.3
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• pp.171-177
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• 2008

Variations in antioxidant capacity of leaves and characteristics of seed germination among five Hibiscus hamabo populations in Korea were evaluated. While the leaves of H. hamabo from Shincheon contained highest Na concentration, those from Hado and Ohzo does lowest. MDA content and SOD activity didn't show significant difference among populations, but total protein and anthocyanin content were significantly different among five populations. The filled seed rates of five populations were ranged from 92.0 to 98.7%, and the moisture contents of seeds from Shinyang and Soando were lower than that of R. syriacus (5.18%). The fresh weights of H. hamabo from Hado and Ohzo were the highest and those of seeds from Shinyang and Soando were the lowest. Significant variations among H. hamabo populations were detected for all seed germination characters: percentage of germination, average germination time and germination rate and uniformity. SOD activities of seeds from Onpyoung and Soando were the highest of five populations, and total protein concentrations of seeds in Ohzo and Shinyang populations were higher than those of other populations. H. hamabo is considered exposed to salt stress and all characteristics of seed germinations were inferior to other species.

• Korean Journal of Plant Resources
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• v.36 no.6
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• pp.580-587
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• 2023

Androsace septentrionalis is a grass species restricted to North Korea; however, it is at the brink of extinction due to habitat loss and environmental changes caused by natural disasters and anthropogenic activities. This study was conducted to characterize the dormancy conditions of A. septentrionalis in an effort to conserve this North Korean plant resource. For this purpose, the morphological characteristics and vigor of A. septentrionalis seeds were examined, and its germination characteristics under different temperature conditions (15/6℃ and 25/15℃ ), low-temperature stratification, and gibberellin (GA₃) treatment were determined. The results revealed that A. septentrionalis exhibits non-deep type morpho-physiological dormancy, and low-temperature stratification treatment was not effective in breaking the dormancy of A. septentrionalis seeds. Meanwhile, GA₃ treatment significantly increased the mean germination time, rate, and speed of the seeds. The optimal conditions for the germination of A. septentrionalis seeds were 25/15℃ fluctuating temperature and 500 mg·L¹ GA₃ treatment. The results of this study are useful for the mass propagation of A. septentrionalis.

• Journal of Ecology and Environment
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• v.37 no.4
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• pp.165-175
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• 2014

A natural population of Adonis multiflora, a spring ephemeral herb growing in temperate deciduous forests, was studied to determine the seed production characteristics. Plant size, flowering time, and seed number were monitored from February 2009 to May 2011 in main growing season (i.e., from March through May). The biomass rates of the shoot and the root in the A. multiflora population were 22-24% and 76-78%, respectively, and the biomass of the root was proportional to that of the shoot. The flowering rate was 60% in the plants with 1 to 2 g of shoot biomass, and 100% in the plants with >2 g of shoot biomass. In the plants with root biomass between 4 and 6 g, the flowering rate was 43% and, in the plants with the root biomass over 8 g, it was 100%. The shoot biomass was a better predictor of the flower production probability than the root biomass. The number of flowers and seeds was closely correlated to shoot biomass at 1% significance level. The size of the plant that produced seed excessively instead of the shoot biomass in one year typically decreased in the next year and vice versa. The flowering time and its duration were closely related to the number of faithful seeds but not to that of total seeds. The number of faithful seeds was proportionate to flowering duration and inversely proportionate to flowering time (year day, YD). In a plant, the number of faithful seeds noticeably decreased with the inflorescence (i.e., order of flower in a plant), and this difference between the two successive flowers was significant at the 1% level between the first and the third flower in 2009 and 2011 but not between the third and the fourth. However, the number of total seeds was mostly similar in the first through the fourth flower for all three years.