Rhododendron Mucronulatum Research Articles

Inhibition of Inducible Nitric Oxide Synthase and Cyclooxygenase‐2 Expression by Phenolic Compounds from Roots of Rhododendron mucronulatum

The roots of Rhododendron mucronulatum Turzaninov have been used in Oriental traditional medicine for the treatment of dysuria, fever, increase of digestive activity and tonics in China and Korea. Activity guided isolation of the roots of Rhododendron mucronulatum Turzaninov has led to the isolation of three flavonoids, one flavan 3-ol and one proanthocyanidin. Chemical investigation of the 80% Me2 CO extract from the roots of Rhododendron mucronulatum led to the isolation and identification of five compounds: taxifolin (1), taxifolin 3-O-β-D-glucopyranoside (2), quercetin 3-O-α-L-arabinofuranoside (3), (-)-epicatechin (4), procyanidin B-3 (5). To investigate the antioxidative and antiinflammatory effects of these compounds, their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated HaCaT cells were also quantified by western blotting and their end products, nitric oxide (NO) and prostaglandin E2 (PGE2 ), respectively. Compounds (1-5) showed potent DPPH radical scavenging compared with positive controls (L-ascorbic acid). Also, compounds 1 and 2 dose-dependently inhibited the expressions of inflammatory mediators, NO and PGE2 , suggesting they are promising candidates as antiinflammatory agents.

Effect of taxifolin glycoside on atopic dermatitis‐like skin lesions in NC/Nga mice

Increased levels of eosinphils, IgE, IL-4, 5, and 13 and pro-inflammatory factors (COX-2, iNOS) are observed in patients with atopic dermatitis (AD). Taxifolin 3-O-beta-D-glucopyranoside (TAX) from the roots of Rhododendron mucronulatum (RM) was examined to determine whether its immunomodulatory effect was applicable for treating atopic dermatitis.A total of 7 groups of NC/Nga mice with AD were treated by topical application or intraperitoneal injection of TAX for 4 weeks. Follow-up evaluations were done to assess the changes in clinical observations, eosinophil counts, and levels of IgE, cytokines, COX-2 and iNOS.In the clinical observation during the experimental period, TAX treatment significantly reduced the severity of AD-like lesions induced in NC/Nga mice. Eosinophil and IgE levels decreased after treatment of the animals with TAX. TAX may thus be associated with improvement of eosinophil-related allergic diseases. The expression of cytokines (IL-4, 5 and 13) was significantly inhibited in the TAX-treated group, suggesting that TAX might play an immunoregulatory role associated with AD. In RT-PCR, iNOS and COX-2 expression levels were reduced in the TAX-treated group. In western blotting, the expression levels of iNOS and COX-2 were also reduced in the TAX-treated group.These findings suggest that TAX is effective for the treatment of AD by preventing the production of inflammatory cytokines and by reducing skin inflammation.

진달래꽃(Rhododendron mucronulatum Flos.) 추출물로부터 Helicobacter pylori 억제 효과를 가지는 phenol성 물질의 정제 및 동정

진달래꽃을 60% ethanol로 추출하여 추출물의 H. pylori에 대한 저해활성의 측정과 저해물질의 분리 및 동정을 시행하였다. 또한 H. pylori균에 대한 항균활성은 60% ethanol 추출물에서 phenol 화합물을 200<TEX>${\mu}g/ml$</TEX> 이상 주입하였을 때부터 22 mm이상의 clear zone이 관찰되어 H. pylori균에 대한 높은 항균력을 나타내었다. 저해물질의 분리는 Sephadex LH-20 column을 이용하여 분리한 결과 6개의 fraction으로 분리되었으며, H. pylori 저해활성을 나타낸 fraction D를 MCI-gel CHP-20 column을 이용하여 normal phase type인 ethanol 100%에서 0%로 농도를 감소시키며 용출한 결과 5개의 단일 물질 분획을 얻을 수 있었다. 그 중 세 가지의 물질에 대해 H. pylori저해활성이 나타나 FAB-MS, <TEX>$^1H$</TEX>와 <TEX>$^{13}C$</TEX> NMR 및 IR spectrum을 사용하여 구조 동정한 결과 quercitrin (quercetin-3-O-rhamnopyranoside), myricitrin (myricetin-3-O-rhamnopyranoside) 및 quercetin인 것으로 확인되었다. The antimicrobial activities of Helicobacter pylori as a functional food source with water and 60% ethanol extracts from Rododendron mucronulatum Turcz. flowers were examined. The total phenol content of 60% ethanol extracts (30.6<TEX>${\pm}$</TEX>0.14 mg/g) from Rododendron mucronulatum Turcz. flowers was higher than that of water extracts (23.2<TEX>${\pm}$</TEX>0.21 mg/g). The inhibitory activities of Rododendron mucronulatum Turcz. extracts on H. pylori was determined to clear zone of 15 mm in 80% ethanol extracts. Purification of inhibitory compounds was carried out in Sephadex LH-20 and MCI-gel CHP-20 column chromatography using a gradient procedure, with increasing ethanol(0<TEX>${\rightarrow}$</TEX>100%) in <TEX>$H_2O$</TEX>. The chemical structure of the purified inhibitory compounds of H. pylori was identified to be quercitrin (quercetin-3-O- rhamnopyranoside), myricitrin (myricetin-3-O-rhamnopyranoside), quercetin by FAB-MS, NMR and IR spectra.

Characteristics of Plant Distribution in the Reclaimed Dredging Area in Gwangyang Bay, Korea

In order to elucidate the mechanisms affecting plant distributions in the reclaimed dredging area in the Gwangyang steelworks, in the Gwangyang Bay, Korea, we examined soil characteristics and plant distributions in four study sites and a control site in the study area. Desalination occurring along a gradient with increasing elevation, resulting in decrease of soil pH, EC, P, K, Cl, Ca, Mg, and salt and an increase in soil T-N, silt, clay contents. From site 1 (the lowest-elevation site) to site 5 (the highest-elevation site), halophytes decreased in abundance and nonhalophytes increased. The dominant species in each site were: Phragmites communis, Limonium tetragonum, and 12 additional species at site 1, Carex pumila, Suaeda japonica, and 15 additional species at site 2, Spergularia marina, Scirpus planiculmis, and 22 additional species at site 3, Miscantus sinensis, Lespedeza bicolor, and 26 additional species at site 4 and Pinus thunberii, Rhododendron mucronulatum, and 39 additional species at site 5, which resembled a naturally-occurring P. thinbergii community. Cluster analysis of the vegetation data matrix grouped the 35 plots into 5 major groups, and cluster analysis using the soil environment data matrix revealed 4 major groups. CCA of the floristic and environmental data matrix showed a positive relationship of SAR, EC, Na, Cl, and Ca, which are related to salt, in the axis and axis, but negative relationships for altitude, organic contents, silt, and clay contents. Notably, plant species in the reclaimed dredging area that were separated along the axis showed strong relationships with factors that related to salt. Long-term exposure to natural rainfall in the reclaimed dredging area changed the soil characteristics, such as salinity. This change in soil characteristics might alter the SAR, which affects plant survival strategies in a given habitat. These results strongly indicated that factors related to salt and elevation play important roles in determining the overall plant distribution in the reclaimed dredging area.

시계열 분석을 이용한 부산지역 계절식물의 개화시기 변화

To examine the trend on the flowering time in some weather flora including Prunus serrulata var. spontanea, Cosmos bipinnatus, and Robinia pseudo-acacia in Busan, the changes in time series and rate of flowering time of plants were analyzed using the method of time series analysis. According to the correlation between the flowering time and the temperature, changing pattern of flowering time was very similar to the pattern of the temperature, and change rate was gradually risen up as time goes on. Especially, the change rate of flowering time in C. bipinnatus was 0.487 day/year and showed the highest value. In flowering date in 2007, the difference was one day between measurement value and prediction value in C. bipinnatus and R. pseudo-acacia, whereas the difference was 8 days in P. mume showing great difference compared to other plants. Flowering time was highly related with temperature of February and March in the weather flora except for P. mume, R. pseudo-acacia and C. bipinnatus. In most plants, flowering time was highly related with a daily average temperature. However, the correlation between flowering time and a daily minimum temperature was the highest in Rhododendron mucronulatum and P. persica, otherwise the correlation between flowering time and a daily maximum temperature was the highest in Pyrus sp.

Immunomodulative and anti-atopic properties of flavonoids from the roots of Rhododendron mucronulatum

Immunomodulative and anti-atopic properties of flavonoids from the roots of Rhododendron mucronulatum

Grayanotoxin Poisoning From Flower of Rhododendron mucronulatum in Humans

Grayanotoxin Poisoning From Flower of Rhododendron mucronulatum in Humans

Grayanotoxin Poisoning From Flower of Rhododendron mucronulatum in Humans

Grayanotoxin Poisoning From Flower of Rhododendron mucronulatum in Humans

Earlier spring in Seoul, Korea

AbstractIn the present study, long‐term changes in the first bloom date of shrub and tree species in Seoul (126.56°E, 37.34°N), Korea were examined using historical observational data for the period 1922–2004 (83 years). The study focused on two shrub species, golden‐bell (Forsythia koreana) and azalea (Rhododendron mucronulatum), and three tree species, cherry (Prunus yedoensis), peach (Prunus persica), and American locust (Robinia pseudoacacia). The annual‐mean temperature has increased by about 2 °C in Seoul over the 83 years analyzed. The temperature increase is significant during the winter and early spring and becomes less significant during late spring. As a result of this regional warming, all five species showed an advance in the first bloom date over this time period. The advanced date is particularly apparent in early‐spring flowering species like golden‐bell (−2.4 days 10‐year−1), azalea (−2.4 days 10‐year−1), cherry (−1.4 days 10‐year−1), and peach (−1.4 days 10‐year−1) as compared to late‐spring flowering species like American locust (−0.5 days 10‐year−1).The present results have demonstrated that the major factor for the determination of flower blooming is heat accumulation, i.e. a certain threshold of growing degree‐days (GDD) index. In particular, early spring flowers were sensitive to the accumulation of warm temperature than late‐spring flowers. Copyright © 2006 Royal Meteorological Society

남해군 삼림식생의 군락생태

1998년 3월부터 2003년 9월까지 남해도 및 인접도서를 포함하는 남해군의 삼림식생에 대해 Z.-M.방법에 의한 식물사회학적 조사를 실시하였다. 그 결과 본 조사지역의 삼림식생은 신갈 나무군락(전형하위군락, 철쭉꽃하위군락), 졸참나무군락(전형하위군락, 당단풍하위군락), 굴참나무군락(전형하위군락, 굴피나무하위군락), 상수리나무군락, 서어나무군락, 소사나무군락, 때죽나무군락, 느티나무군락, 히어리군락, 소나무군락(전형하위군락, 진달래하위군락, 서어나무하위군락), 곰솔군락(전형하위군락, 사스레피나무하위군락), 산철쭉군락, 편백식재림, 사방오리식재림, 리기다소나무식재림, 아까시나무식재림, 삼나무식재림 등 총 12군락, 11하위군락, 5식재림으로 구분되었다. 본 조사지역 삼림의 토양분석결과 삼림토양의 pH는<TEX>$4.2\sim5.4$</TEX>의 범위를 나타내었으며, 함수량은 유기물함량과 유의성이 높은 가운데 산철쭉군락이 가장 높고, 소나무군락이 가장 낮게 나타났다. 유기물함량은 신갈나무군락, 소사나무군락, 졸참나무군락에서 비교적 높게<TEX>$(15.8\sim19.1%)$</TEX> 나타났고, 상수리나무군락, 히어리군락, 곰솔군락에서는 낮게<TEX>$(3.3\sim5.4%)$</TEX> 나타났다. 식재림은 대부분 낮았으며. 리기다소나무식재림(2.8%)과 삼나무식재림(5.6%)이 가장 낮았다. 치환성 양이온(<TEX>$K^+$</TEX>, <TEX>$Ca^{2+}$</TEX> and <TEX>$Mg^{2+}$</TEX>)사이에는 높은 상관관계가 있는 것으로 나타났다. The forest vegetation of Namhae-gun was investigated using the methodology of the Z.-M. school of phytosociology from March, 1998 to September, 2003. The forest vegetation was classified into 12 communities, 11 subcommunities, 5 afforestations as follows : Quercus mongolica community(typical subcommunity, Rhododendron schlippenbachii subcommunity), Ouercus serrata community(typical subcommunity, Acer pseudo-sieboldianum subcommunity), Ouercus variablis community(typical subcommunity, Platycarya strobilacea subcommunity), Quercus acutissima community, Carpinus laxiflora community, Carpinus coreans community, Styrax japonica community, Zelkova serrata community, Corylopsis coreana community, Pinus densiflora community(typical subcommunity, Rhododendron mucronulatum subcommunity, Carpinus laxiflora subcommunity), Pinus thunbergii community(typical subcommunity, Eurya Japonica subcommunity), Rhododendron yedoense var. poukhanense community, Chamaecyparis obtusa afforestation, Alnus firma afforestation, Pinus rigida afforestation, Robinia pseudo-acacia afforestation, Cryptomeria japonica afforestation. The soil pH of the study area was ranged from 4.2 to 5.4, and soil moisture content was strongly related to organic matter content. The Corylopsis coreana community contained the highest soil moisture content, whereas Pinus densiflora community contained the lowest one. The content of organic matter were <TEX>$15.8\sim19.1%$</TEX> in the Quercus mongolica, Carpinus coreans and Ouercus serrata communities, <TEX>$3.3\sim5.4%$</TEX> in the Quercus acutissima, Corylopsis coreana and Pinus thunbergii communities, and <TEX>$2.8\sim5.6%$</TEX> in the Pinus rigida and Cryptomeria japonica afforestation. There is significant correlation among the contents of cations(<TEX>$K^+$</TEX>, <TEX>$Ca^{2+}$</TEX> and <TEX>$Mg^{2+}$</TEX>).

영종도 삼림식생의 군락생태

영종도의 삼림식생은 곰솔군락, 소나무군락, 상수리나무군락, 신갈나무군락, 졸참나무군락, 굴참나무군락, 갈참나무군락, 떡갈나무군락, 소사나무군락, 물박달나무군락의 10개 이차림과 리기다소나무식재림, 아까시나무식재림, 밤나무식재림 등 3개 식재림으로 구분되었다. 상대기여도(R-NCD)에 의한 계층별 우점종은 아교목층에서 상수리나무, 소나무, 굴피나무, 팥배나무, 갈참나무, 관목층에서 진달래, 굴피나무, 졸참나무, 갈참나무, 상수리나무, 초본층에서 그늘사초, 산거울, 진달래, 억새, 주름조개풀 등으로 대부분 건조한 환경에 주로 출현하는 종들로 구성되어 있으며 군락의 층상구조 발달은 빈약하였다. 흉고직경 분포는 각 군락별로 다소 차이가 있었으나 대체로 2∼10 ㎝ 범위의 소경목이 전체의 56%를 차지하였으며 인위적 교란 후 재생과정 중에 있는 식생으로 수령은 40년 이내인 것으로 조사되었다. 군락별 토양환경의 pH는 전체평균값이 4.73(4.53∼5.10)으로 나타났으며, 유기물함량은 산지대에 분포하는 신갈나무군락, 리기다소나무식재림, 밤나무식재림이 산지 능선부나 해안가, 저지의 구릉지에 주로 분포하는 곰솔군락, 소나무군락에 비하여 각각 높게 나타났으며, 유기물함량과 총질소 사이에는 높은 상관관계를 보였다. The vegetation in this study area was divided into 10 plant communities: Pinus thunbergii, P. densiflora, Quercus acutissima, Q. mongolica, Q. serratea, Q. variabilis, Q. aliena, Q. dentata, Carpinus coreana, Betula davurica and 3 afforestations; Pinus rigida, Robinia pseudo-acacia, Castanea crenata. The dominant species in each stratum as determined by R-NCD appeared to be Q. acutissima, P. densiflora, Platycarya strobilacea, Sorbus alnifolia and Q. aliena in the tree-2 layer, Rhododendron mucronulatum, P. strobilacea, Q. serrata, Q. aliena and Q. acutissima in the shrub layer, and Carex lanceolata, C. humilis, R. mucronulatum, Mischanthus sinensis var. purpurascens and Oplismenus undulatifolius in the herb layer. The distribution of diameter at breast height(DBH) showed the highest percentage (56%) in the range of 2∼10㎝ in the study area and it was investigated as being in the restoration phase after disturbance. The average of the age of trees was under 40-years-od. The pH of soil collected at each site appeared to be within the range between 4.53 and 5.10(the average of 4.73) in each community, organic matters appeared higher than the value in Q. mongolica, P. rigida, C. crenata communities compared to P. thunbergii, P. densiflora communities. And soil organic matters and total nitrogen were highly correlated with their contents.

Host Range of a Select Isolate of the Beneficial Ericoid Mycorrhizal Fungus Hymenoscyphus ericae

Studies were conducted to examine the host range of a select isolate of the ericoid mycorrhizal fungus, Hymenoscyphus ericae (Read) Korf and Kernan [American Type Culture Collection (ATCC) #32985]. Host status was tested for 15 ericaceous species, including Calluna vulgaris, Enkianthus campanulatus, Gaultheria procumbens, Kalmia latifolia, Leucothoe fontanesiana, Oxydendrum arboreum, Pieris floribunda, Rhododendron calendulaceum, Rhododendron carolinianum, Rhododendron catawbiense, Rhododendron maximum, Rhododendron mucronulatum, Vaccinium corymbosum, and Vaccinium macrocarpon. Arbutus unedo, an ericaceous species that forms arbutoid, not ericoid, mycorrhizae was used as a negative control. All of the species were colonized by the ericoid isolate with the exception of Enkianthus campanulatus and the negative control. The benefits of the association and possible commercial applications are discussed.