• Applied Biological Chemistry
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• v.51 no.4
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• pp.334-337
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• 2008

• Food Science and Biotechnology
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• v.18 no.3
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• pp.808-812
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• 2009

The ${\alpha}-glucosidase$ inhibitory and antioxidant effects of water chestnut (Trapa japonica Flerov.) were assessed to explore its possible use as an anti-diabetic agent. Methanol extracts of the fruit shell and meat of water chestnut were assayed for inhibitory activity against yeast ${\alpha}-glucosidase$ and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Effect of fruit shell extract on postprandial glucose response was assessed. Compared with fruit meat, shell extract showed stronger inhibition against ${\alpha}-glucosidase$ with an $IC_{50}$ of 273 ${\mu}g/mL$. Oral administration of fruit shell extract (500 mg/kg) significantly lowered the postprandial area under the glucose response curve to starch (1 g/kg) in streptozotocin (STZ)-induced diabetic rats (p<0.01). Compared with fruit meat, shell extract showed stronger scavenging activity against DPPH, with an $IC_{50}$ of 27.1 ${\mu}g/mL$. The results indicate that the fruit shell of water chestnut was effective in controlling postprandial hyperglycemia and exerted an antioxidant effect. Therefore, water chestnut may be useful in treating diabetes.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.4
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• pp.307-312
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• 2023

Water chestnut is fruits of Trapa natans var. bispinosa grown wild in Korea. In this study, water chestnut was investigated for anti-pigmentation. Treatment with ethanolic extracts of water chestnut significantly reduced production of melanin in α-MSH simulated B16F10 cells. At 200 ㎍/mL ethanolic extracts of water chestnut, melanin contents were repressed by 43.26% compared to the control group. Additionally, ethanolic extracts of water chestnut reduced expression and activity of tyrosinase, key enzyme in melanogenesis, in α-MSH simulated B16F10 cells. Ethanolic extracts of water chestnut downregulated tyrosinase activity and expression to 23.65% and 62.35%, respectively. These results suggest that ethanolic extracts of water chestnut might be used as a promising whitening ingredients for inhibition of α-MSH-induced melanin synthesis and pigmentation.

• Journal of Wetlands Research
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• v.7 no.1
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• pp.129-138
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• 2005

The flora and vegetation of Jang-cheok wetland (Gyeong-nam) was investigated from April 1. 2004 to Feburary 28. 2005. The vegetation plants collected from this area were 18 taxa : 18 species 17 genera 14 families. Hygrophtes were 2 species 2 genera 2 families. Emergent plants were 6 species 5 genera 6 families. Submersed plants were 1 species 1 genera 1 families. Floating-leaved plants were 5 species 5 genera 5 families. Free-floating plants were 2 species 3 genera 2 families. Dominance of life form was investigated Trapa japonica, Phragmites commnis, Leersia japonica by 5 dominance values and Hydrocharis dubia, Ceratophyllum dmersum were 1 dominance values. The community was investigated 5 communities : Leersia japonica community. Trapa japonica community. Nelumbo nucifera community. Miscanthus sacchariflorus community. Phragmites communis community. Dominance species(Leersia japonica) of Leersia japonica community was investigated $1,89g/m^{2}$(Dry weight) and $1,730ind./m^{2}$(Density). Doninance species(Trapa japonica) of Trapa japonica community was investigated $36,25g/m^{2}$(Dry weight) and $15.20ind./m^{2}$(Density). Dominance species(Nelumbo nucifera) of Nelumbo nucifera community was investigated $30.59g/m^{2}$(Dry weight) and $11.20ind./m^{2}$(Density). Dominance species(Miscanthus sacchariflorus) of Miscanthus sacchariflorus community was investigated $180.50g/m^{2}$(Dry weight) and $124.80ind./m^{2}$(Density). Dominance species(Phragmites communis) of Phragmites communis community was investigated $159.50g/m^{2}$(Dry weight) and $60.00ind./m^{2}$(Density). The predominant species of this area was investigated Trapa. Japonica and the other communities was only small area in the waterside area.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.305-313
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• 2002

The physico-chemical characteristics of water and sediment, and structures of vegetation of the vascular hydrophytes were investigated in the West Nakdong River. Water quality was eutrophic according to the mean values and the ranges of water properties such as pH, DO, BOD, chlorophyll a, total nitrogen and phosphate, and other nutrients. A few cases were hypereutrophic for chlorophyll a level in summer. Soil reaction was weak acid. Composition of sediment was mainly sand except in SI(Sinan chideung) of which was mainly clay, and SU(Suan chideung) of which was mainly silt. Flora of vascular hydrophyte had 26 species and 1 variety comprising 16 families. Trapa japonica was dominant species in the sites of DU(Dunchido), GA(Garak chideung) and SU. Nymphoides peltata and Hydrocharis dubia dominated in DA and SI, respectively. Species diversity and evenness were relatively high in SI and SU but dominance was high in DA. After June, water lettuce(Pistia stratiotes) and water hyacinth(Eichhornia crassipes) were flowed from tributary to the river. Standing crop of macrohydrophytes was high in DA from April to August, but it showed maximum standing crop (445g·dw/㎡) in DU after disturbance by explosive growth of exotic plants in October. In comparison with those in 1985, total productivities in DU and GA decreased to 33.5%, and the reduction ratio of dominant species, Trapa japonica was 56.7%. Najas marina, N. minor, Myriophyllum spicatum and Nymphoides indica have disappeared ever since the Nakdong barrage was constructed in the Nakdong river. They were divided into three groups (GA-SU-DU, DA, SI) by cluster analysis. Introduction of the exotic species in this river caused decreasing of endemic plants including endangered species Euryale ferox and rare species Hydocharis dubia, and food plants for waterfowl such as Trapa japonica, Vallisneria asiatica and Potamogeton crispus.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.657-664
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• 2011

The plant community of water`s edge was investigated using the methodology of the Z-M school of phytosociology, from March to October, 2008, 2011. The results were obtained as follow ; hygrophyte hydrophye of 2008 year of this area consist of 38 taxa : 1 varieties, 37 species, 31 genera, 21 families and 14 orders, hygrophyte hydrophye of 2011 year of this area consist of hygrophyte 15 species, 13 species were reduced by approximately 13.33%. And emerged hydrophyres did not show a change. 9 species, 4 species of Floating-Leaved hydrophyres 55.56%, Submerged hydrophyres of the 4 species, 1 species, 75%, Free-Floating hydrophyres remarkable I the 3 species was reduced to 33.33%, respectively. Plants Community of the water's edge was classified into 16 communities as follows; (Leersia japonica community, Spirodela polyrhiza community, Miscanthus sacchariflorus community, Hydrocharis dubia community, Zizania latifolia community, Paspalum distichum var. indutum community, Leersia japonica-Hydrocharis dubia community, Salix glandulosa community, Trapa japonica community, Humulus japonicus community, Nelumbo nucifera community, Carex dimorpholepis community, Salix koreensis community, Trapa japonica-Spirodela polyrhiza community, Persicaria thunbergii). Higher in 2011 than in 2008, the ratio was reduced to Leersia japonica community. Between July-August by a sudden change in the rate of water storage changes in vegetation are thought to have appeared.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.157-168
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• 2017

Backswamp is the section of a floodplain where deposits of fine silts and clays settle after a flood. In general, the wetland is composed of diverse ecosystems, and is characterized by ecotone. The purpose of this study was to analyze vegetation naturalness and to assess vegetation value by syntaxonomy and synecology of Useupje backswamp at Yeongsan river. As a result, the vegetation was divided into four physyiognomy types and 14 vegetation units depending on the species composition and habitats. The vegetation units confirmed in the study were as follow: Spirodela polyrhiza community as floating plant; Trapa bispinosa var. inuma community and Trapa bispinosa var. inumai-Nelumbo nucifera community as floating-leaved plant; Paspalum distichum community, Persicaria thunbergii community and Phalaridetum arundinaceae as lentic vegetation in the eulittoral zone; Scirpo fluviarilis-Zizanietum latifoliae and Typha angustata community in the emerged zone; Scirpetum tabernaemontani and Phragmitetum australis in the littoral zone; Carex dimorpholepis-Salix subfragilis community ecotone region of upland. According to the study, the vegetation distribution was highly affected by water level and artificial interference. Moreover, the development of vegetation units showed a significant relationship between species composition and habitats. Although vegetation value of Useupje resulted by vegetation naturalness was identified as the grade [III], the ecological value is expected to upward evaluation because of unique vegetation and geographical location.

• Korean Journal of Weed Science
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• v.17 no.4
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• pp.413-420
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• 1997

In this study, germination characteristics and effect of some chemicals on germination of Trapa japonica $F_{EROV}$ seeds were investigated to obtain a fundamental data for controlling them. When the seeds were stored at low temperature for at least 3 months, their dormancy was completely released with a germinability of above 90%. However, those stored under the room or high temperature condition were never germinated. Germination was best at constant temperature of around $25^{\circ}C$ or at alternate temperature of 25/$15^{\circ}C$ (12 hr-day/12 hr-night), and was nat dependent on light. They could germinate though planted at the depth of 15 cm, but their initial growth were: suppressed with increase of planting depth, especially above 10 cm depth. Germinability was lost when the fresh weight was decreased more than 30%, indicating that the seed is sensitive to dehydration. The freezing at $-20^{\circ}C$ for 1 hr didn't affect germination, but 5 hr treatment completely killed them. Their germination was inhibited by 100% at 100 ppm ABA and slightly inhibited above 25 ppm of butachlor, whereas pyrazosulfuron-ethylnt is likely to control T. japonica physically and herbicide treatment to inhibit germination may not be recommendatory. and bensulfuron-methyl didn't inhibit the germination at the concentration of 100 ppm. Taken together, dehydration treatme is likely to control T. japonica physically and herbicide treatment to inhibit germination may not be recommendatory.

• Journal of Wetlands Research
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• v.5 no.2
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• pp.67-81
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• 2003

Vegetation structure was investigated in the Hwapo wetland around the Nakdong-gang, Gimhae-city, Gyeongsangnam-do, Korea from May to August, 2001. The vegetation type was classified into 18 communities based on the actual vegetation map: Phragmites communis community, Miscanthus sacchariflorus community, Salix nipponica community, Echinochloa crus-galli var. frumentacea community, Zizania latiofolia community, Cyperus amuricus community, Spirodela polyrhiza community, Trapa japonica community, Phragmites communis-Miscanthus sacchariflorus community, Salix nipponiaz-Misaznthus sacchariflorus community, Cyperus amuricus-Acorus calamus var. angustatus community, Salvinia natans community, Hydrilla verticillata-Spirodela polyrhiza community, Persiazria maackiana community, Trapa japonica-Salvinia natans community, Hydrilla verticillata community, Potamogeton crispus community, and Populus deltoides community. Among them, Phragmites communis community was the largest (34.9 ha, 29.53%). The dominant vegetation type was Persiazria hydropiper - Persicaria maackiana community based on the phytosociological method, and it was classified into four subcommunities: Phalaris arundinacea-Salix nipponica subcommunity, Miscanthus sacchariflorus subcommunity, Phragmites communis subcommunity, and Spirodela polyrhiza subcommunity, and Acorus calamus var. angustatus group belongs to Miscanthus sacchariflorus subcommunity.

• Korean Journal of Environment and Ecology
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• v.29 no.1
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• pp.81-87
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• 2015

This study was carried out in the peatland for estimating the paleoenvironment based on the analysis from its fossils plant and radiocarbon at the Hwayang-ri, Hyeondeok-myeon, Pyeongtaek-city, South Korea. Variety of fossil was collected from the peatland which could discriminated with naked eye and sorted into seeds, leaves, stems from four-stage of standard sieve. During analysis for the large plant fossil within the peatland, the dead plants were largely divided into 3 fossil zones according to its peatland. In the fossil zone III (the oldest layer; 6,970~6,070 yr $C^{14}$ B.P.), the observation of leaves of hydrophyte such as Trapa sp. and stems of Alnus japonica which appeared in wetland means that the environment was influenced by the climate changes such as rainfall increasing and sea level rise. In the fossil zone II (the middle layer; 6,070~5,800 yr C14 B.P.), the occurrence of Gramineae, Cyperaceae and Fagaceae indicate that the environmental condition might be more or less dry by decreasing rainfall and drop in sea level. The fossil zone I (the recent layer; 5,800~4,540 yr $C^{14}$ B.P.) where lots of herbaceous plants, increasing of Fagaceae, decreasing of A. japonica. and distribution of Pinaceae were showed, was inferred to be repeated both dry and wet environment due to human disturbance.