• The Korean Journal of Ecology
• /
• 제21권5_2호
• /
• pp.519-529
• /
• 1998

The vegetation of alpine and subalpine zone from timber line, 2,000m altitude, to the upper area of Mt. Packtu were investigated by phytosociological method. The plant distribution along to the different altitudes shown as follows: Betula ermani community with Rhododendron redowskianum occupied dominantly at 2,000m area as patch forms, Rhododendron redowskianum community with Vaccinium uliginosum, at 2,180-2,200m area, both Vaccinium uliginosum and Rhododendron redowskianum community were compatible with each other at 2,243m area. Rhododendron redowskianum community at 2,250, Salix rotundifolia community, Erigeron thunbergii var. glabrata community, Dryas octopetala var. asiatica community and Carex atrata community were occurred frequently at 2,263m around Chonji Lake. Rhododendron aureum, Thunbergii coccinea and V accinium uliginosum showed higher cover degree than other species at 2,370m area, Phyllodoce coerulea-Rhododendron aureum community at 2,400m, Rhododendron redowskianum community at 2,470m, Rhododendron aureum community at 2,490m, Salix rotundifolia at 2,520m, Rhododendron redowskianum community at 2,580m, Dryas octopetala var. asiatica community, Salix rotundifolia, and bistorta achotensis etc. at 2,650 altitude area were settled as sparse, creeping shape on the surface soil and dwarf plants of about 15cm heights.

• Journal of Forest and Environmental Science
• /
• 제40권2호
• /
• pp.123-140
• /
• 2024

More than half of the global distribution of the Rhododendron genus is found in China, with over 74% being endemic species. However, there is still insufficient data to chemically classify the Rhododendron genus native to China. Therefore, in this study, a chemotaxonomic study was conducted to determine the presence of taxifolin-3-O-arabinopyranoside, a flavonoid compound, in the Rhododendron genus native to China. Forty-three species of Rhododendron native to China-20 from across China, 8 from Beijing, 6 from Yanbian, and 9 from Yunnan-were utilized in the experiment. Through HPLC analysis, the retention time was compared with that of taxifolin-3-O-arabinopyranoside, a standard compound, and quantitative analysis was conducted. As a result, taxifolin-3-O-arabinopyranoside was detected in 22 out of 43 the Chinese Rhododendron species. Afterwards, LC-MS/MS analysis was performed on the 22 species in which taxifolin-3-O-arabinopyranoside was detected to determine whether the molecular weight was consistent with the standard compound. Under negative conditions, it was confirmed that all samples exhibited the same molecular weight as taxifolin-3-O-arabinopyranoside, 435-436 m/z. The same compound was detected in more than half of the Rhododendron species used in the experiment, and taxifolin-3-O-arabinopyranoside was determined to be an indicator compound for Rhododendron species native to China. In addition, the possibility of using the above results as basic data for chemical classification of Chinese Rhododendron genus was confirmed.

• 한국환경과학회지
• /
• 제20권10호
• /
• pp.1319-1328
• /
• 2011

Rhododendron brachycarpum is a evergreen broad-leaved shrub and belongs to the Ericaceae family and the Rhododendron genus. It is well known for its beautiful leaves and flowers. There are 11 species of the Rhododendron genus in Korea. It includes 3 species - Rhododendron brachycarpum, Rhododendron aureum Georgi and Rhododendron brachycarpum var. roseum Koidz. They grow naturally over 1,000 meters above sea level of the Baekdu Mountain Range in Korea. These habitats, according to investigations of 9 Rhododendron brachycarpum natural habitats, are mostly located on the slope of mountains facing north at an altitude of 1,200 m to 1,526 m above sea level with angle of inclination from 30 degrees to 45 degrees. Based on the result of vegetation analysis of dominance species in the quadrates, there are Quercus aliena, Quercus mongolica Fisch. ex Ledeb, Abies holophylla in species of upper trees, and so on. Dominant species of woody plants in tree layer are Quercus aliena, Quercus mongolica Fisch. ex Ledeb, Abies holophylla, Betula platyphylla and Veeatrum patulum Loes. fil, Erythronium japonicum, Dryopteris crassirhizoma, Paeonia japonica var. glabra Makino are founded in herbaceous plants. And we can see another result of the investigation that the flowering rates of the plants with the buds are highly ranked mountains such as Mt. Hambaek 68%, Mt. Gyebang 40%, Mt. Yagksu 9%, Mt. Gaein 7% and Mt. Seolag 0%. The results show that there are 24 over 15-year-old Rhododendron brachycarpums in Mt. Odae and are 56 under 15-year-old trees in Mt. Hambaek and are no trees in Mt. Gyebang and are 9 over 30-year-dead trees only in Mt. Taebaeg. Out of found trees, the highest tree is 7 m in height and 0.6 m in diameter. Also this result shows what are the vulnerability factors of the natural habitats. They are as follows: indiscriminate trails in mountains, damages by mountain climbers, uncareful plant collecting, the fierce competitions with other plants such as Acer pseudosieboldianum var. ishidoyanum Uyeki, Quercus aliena, Celastrus orbiculatus and damages by disease and insect, unusual temperature in natural habitats, etc. Rhododendron brachycarpums have high ornamental value and excellent pharmaceutical effect. But the areas of its habitats decrease dramatically. So we need measures to protect and their natural habitats. It is necessary that we conductfurther investigations to designate conservation area for Rhododendron brachycarpums.

• 한국임상수의학회지
• /
• 제26권4호
• /
• pp.344-347
• /
• 2009

2-4세령의 면양 4두와 1-3세령의 한국재래산양 5두가 정원수를 가지치기 한 후 던져준 철쭉 (Rhododendron schlippenbachii)을 섭취하고 난 후 다음날 식욕감퇴, 무기력, 욕지기, 침흘림, 구토, 호흡곤란, 비틀거림, 서맥 등의 중독증상을 나타내어 철쭉중독으로 진단한 후 atropine과 carbo-pulbit를 처치하였다. 처치 후 8시간째에 1두의 한국재래산양이 폐사되어 부검을 실시한 결과 위 내에서 다량의 철쭉잎이 관찰되었으며, 나머지 면양과 한국재래산양은 3일 이내에 모두 회복되었다.

• 한국환경복원기술학회지
• /
• 제2권4호
• /
• pp.47-53
• /
• 1999

상록성인 히노데 기리시마 철쭉(Rhododendron obtusum cv. Hinodegiri)과 반상록성인 산철쭉(Rhododendron yeooense var. poukhanense)의 늦겨울부터 초봄까지의 생장상태를 비교하여 이 시기에 발생하는 피해 원인을 규명하고자 실험한 결과는 다음과 같다. Dehardening후 개화기의 관상가치는 산철쭉의 경우 관수처리 및 차광처리에 따른 관상가치에 별다른 차이가 없었다. 그러나 상록성 왜철쭉의 경우에는 특히 차광처리구에서 대조구나 관수처리구에 비해 높은 관상가치를 나타내었다. Dehardening과정의 동사점의 변화는 두 종류 모두에서 2월부터 3월까지의 기간에 급격한 변화가 이루어져 이 시기가 dehardening의 중요한 시기임을 알 수 있었다. 한편 이 시기에 상록성 왜철쭉은 차광처리구에서 대조구에 비해 $3^{\circ}C$ 정도 낮은 동사점을 기록하였으며, 관수처리구에서는 $1^{\circ}C$ 높은 동사점을 나타내었다. 같은 시기의 가지의 수분포텐셜과 수분함량의 변화를 측정 한 결과, 두 종류 공히 모든 처리구에서 2월부터 5월까지 지속적인 증가를 보였다. 이때 산철쭉의 경우는 5월에 대조구에 비해 차광처리구가 수분포텐셜 0.3MPa, 수분함량 3% 정도 높아 거의 비슷한 체내수분상태를 유지하였지만, 상록성 왜철쭉의 경우는 대조구에 비해 차광처리구에서 수분포텐셜이 0.9MPa, 수분함량은 11%가 높게 나타났다. 한편 관수처리구에서는 토양으로부터의 수분공급이 어느 정도 이루어지더라도 광션에 의한 수분손실량의 증가가 크기 때문에 체내수분의 완전한 회복이 어려웠던 것으로 생각되었다. 체내수분의 회복정도의 차이는 TTC법을 이용한 가지활력의 측정결과에서도 나타나 특히 상록성 왜철쭉의 대조구에 비해 차광처리구에서 훨씬 높은 가지활력을 나타내었다. 이상의 결과를 종합할 때 상록성 왜철쭉의 피해는 겨울철 동안 지속되었던 수분손실의 상태에서 봄철의 dehardening 시기에 체내수분을 원래의 상태대로 회복할 수 있는지의 여부에 따라 결정되는 것임을 알 수 있었으며, 이때 체내수분의 회복을 위해서는 외부로부터의 수분공급보다는 수분손실을 줄이는 것이 중요하며 그를 위해 차광처리가 효과적인 방법임을 알 수 있었다.

• 식물분류학회지
• /
• 제52권2호
• /
• pp.102-107
• /
• 2022

Rhododendron keiskei var. hypoglaucum (Ericaceae) was recently reported in Korea, with a disjunct distribution on the southern islands of the Korean Peninsula. Although chromosome numbers and ploidy variations are important traits in angiosperms, gaining a clear understanding the cytological features of Rhododendron has been hampered by the small size of its chromosomes. We herein report the chromosome number, karyotype structure, and genome size of R. keiskei var. hypoglaucum for the first time. The chromosome number of the investigated plants was 2n = 26 with x = 13 as the base chromosome number, which is the one of the frequently encountered base chromosome numbers in Rhododendron. The karyotype of R. keiskei var. hypoglaucum is composed of metacentric and submetacentric chromosomes similar in length, which ranged from 1.39 to 2.40 ㎛. The DNA 1C-value in all examined accessions was small, ranging from 0.63 to 0.65 pg, further supporting the stable genome size in Rhododendron. These comprehensive cytological results provide a framework for detailed molecular, cytogenetic, and phylogenomic analyses that can be used to interpret the slow species diversification rate in Rhododendron.

• Journal of Forest and Environmental Science
• /
• 제38권3호
• /
• pp.159-173
• /
• 2022

Genus of Rhododendron has been used in traditional medicine since ancient times and is known to be effective in immune function, inflammation, and cold symptoms. And the reason for this activity is the flavanonol type among flavonoids in the genus of Rhododendron. Among the flavanonol types, Taxifolin-3-O-arabinopyranoside was isolated from the root of native R. mucronulatum in Korea, and the structure was finally identified through HPLC, LC-MS/MS, ¹H-NMR, and ¹³C-NMR. Taxifolin-3-O-arabinopyranoside is a compound mainly found in R. mucronulatum, a representative species of the genus of Rhododendron, and exhibits antioxidant, anti-inflammatory, and anti-atopic activities. In this study, Taxifolin-3-O-arabinopyranoside was chemotaxonomic significant in 5 species of the genus Rhododendron native to Korea (R. mucronulatum, R. mucronulatum var. ciliatum, R. schlippenbachii, R. yedoense var. Poukhanense, R. japonicum for. Flavum). Compared with the existing literature, Taxifolin-3-O-arabinopyranoside was identified for the first time in 4 species of Rhododendron except for the R. mucronulatum.

• Applied Biological Chemistry
• /
• 제48권3호
• /
• pp.280-284
• /
• 2005

Several biological activities of Rhododendron mucronulatum were investigated. The electron donating abilities of ethanol extracts of Rhododendron mucronulatum were more than 90% at 100 ppm, 500 ppm and 1,000 ppm. Xanthine oxidase was inhibition about 46% by the ethanol extracts of R. mucronulatum at 500 ppm 48% of tyrosinase activity relating to skin-whitening was shown at 1,000 ppm. Uniquely, the anti-microbial effects of water extract and ethanol extract were shown only on Staphylococcus aureus. The water extract 1 mg/disc showed the higher activity than ethanol extract. The growth inhibition effect of each sample on lung cancer (A549) and melanoma (B16F10) cell lines were over 70% at 1,000 ppm, while the effects on the melanoma (G361) and liver cancer (HepG2) were about 50% at the same concentration.

• Archives of Pharmacal Research
• /
• 제9권4호
• /
• pp.233-236
• /
• 1986

The flavonoids isolated form the leaves of rhododendron brachycarpum were identified as quercetin, avicularin, quercitrin and hyperin.

• 생약학회지
• /
• 제22권1호
• /
• pp.18-21
• /
• 1991

Campanulin, ${\alpha}-amyrin$, ${\beta}-amyrin$, uvaol, simiarenol, ursolic acid and oleanolic acid were isolated from the ethyl acetate fraction of the leaves of Rhododendron brachycarpum and their structures were identified by spectroscopic and chemical methods.