• Journal of Ecology and Environment
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• 제33권2호
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• pp.121-131
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• 2010

Betula platyphylla var. japonica and Betula ermanii segregate vertically at an elevation of approximately 1,850 m on Mt. Neko in Nagano Prefecture, Japan. B. platyphylla var. japonica and B. ermanii were the dominant species below and above this altitude, at which the mean-annual and growing-season air temperatures were $4^{\circ}C$ and $14.1^{\circ}C$, respectively. Based on a modification of Kira's warmth index which employs cumulative temperature represented as $^{\circ}C$ day, leaf unfolding in both species was observed to be initiated at $58^{\circ}C$ day and $169^{\circ}C$ day, respectively. In 1996, leaf unfolding was initiated on 18 May in B. platyphylla var. japonica (+/-6 days) and on 5 June in B. ermanii (+/-8 days), shortly after the last frost which occurred on 5 May 1995 above 1,850 m; below this elevation there was no risk of frost at the time. At elevations above 1,850 m, the unfolded leaves of B. platyphylla were damaged by late frost, while B. ermanii escaped injury because the leaves were still protected by winter buds. The optimum temperature for seed germination in both B. platyphylla and B. ermanii was $30^{\circ}C$. Temperature alternation from 10 to $30^{\circ}C$ and moist storage of seeds at $4^{\circ}C$ (stratification) prior to incubation increased germination rates in both species. The seedlings of B. ermanii had a greater survival rates than those of B. platyphylla var. japonica when planted above 1,850 m. Comparisons of the timing of leaf unfolding and the latest frost at a site appeared to be the main factors affecting the vertical distribution of these species.

• Archives of Pharmacal Research
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• 제15권3호
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• pp.211-214
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• 1992

Chemical examination of Betula platyphylla var. latifolia afforded a novel diarylheptanoid named betulateraol, together with a phenylpropanoid (3, 4'-dihydroxypropio-phenone), flavan-3-ol [(+)-catechin] and its glycosides [(+)-catechin 5-O-$\beta$-glucopyranoside, (+)-catechin 7-0-$\beta$-D-glucopyranoside] and two proanthocyanidins (procyanidins B-1 and B-3).

• 생약학회지
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• 제25권3호
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• pp.199-203
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• 1994

Chemical examination of the leaves of Betula platyphylla var. latifolia has led to the isolation and characterization of five flavonoid glycosides including two C-glucosyl flavonoids. The structures of these compounds were elucidated as myricetin $3-O-{\alpha}-_L-rhamnoside$ (myricitrin), $quercetin-3-O-{\beta}-_D-glucopyranoside$ (isoquercitrin), $quercetin-3-O-{\beta}-_D-glucopyranoside$ (hyperoside), $nalingenin-6-C-{\beta}-_D-glucopyranoside$ (hemiphloin) and $aromadendrin-6-C-{\beta}-_D-glucopyranosidre(6-C-glucosyldihydrokaempferol)$ on the basis of physico-chemical and spectroscopic evidences.

• 한국산림과학회지
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• 제90권1호
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• pp.55-63
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• 2001

이 연구는 대표적인 속성수인 이태리 포플러와 자작나무가 쓰레기 매립지주변의 조림 수종으로서 적당한가를 평가하기 위해서 수행되었다. 두 수종 묘목에 대한 침출수 관수 효과를 알아보기 위해서 침출수 원액, 50% 침출수, 25% 침출수 그리고 대조구(수도물) 등 4가지 침출수로 다르게 희석하여 약 3개월 정도 관수했다. 이태리 포플러와 자작나무 공통적으로 묘고, 근원경, 물질생산량 모두 침출수 원액을 관수한 처리구가 다른 처리구보다 좋았다. 침출수 원액으로 관수한 묘목의 엽록소 지수, 광합성능력, 증산량이 수도물로 관수한 대조구보다 모두 유의하게 높음을 보여주었다. 이는 비록 3개월이라는 짧은 기간의 결과이긴 하지만, 이들 두 수종은 매립지 주변의 조림, 복구를 위해서 좋은 추천 수종임을 보여주고 있다.

• 대한본초학회지
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• 제28권3호
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• pp.45-51
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• 2013

Objectives : This study was conducted to measure the antioxidative and antimicrobial activities of water- and ethanol-extracts from Betula platyphylla var. japonica, Punica granatum and Rhus javanica against various species of anaerobic bacteria. Methods : In order to evaluate the antioxidative and antimicrobial activities of water- and ethanol-extracts, DPPH radical scavenging and superoxide dismutase (SOD)-like activities were measured in various species such as Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Propionibacterium acnes that induce skin inflammation. Also the total amount of phenol in each water- and ethanol-extract was measured to identify its role in the antioxidative and antimicrobial activities of water- and ethanol-extracts from Betula platyphylla var. japonica, Punica granatum and Rhus javanica. The antibacterial activity of the extracts was measured by confirming the lowest concentrations in disk diffusion and minimum inhibitory concentration (MIC) tests. Results : It was observed that RJE (Rhus javanica-EtOH extracts) show the highest content of total phenol. In addition, for RJE the total phenol content was higher from samples taken from domestic sources than from samples taken from foreign sources. DPPH radical scavenging activity was increased by treatment with PGE (Punica granatum-EtOH extracts), RJE and RJW (Rhus javanica-water extracts). It was observed that SOD-like activity was highest in the treatment with PGE. All of the extracts showed antimicrobial activity on S. epidermidis, S. aureus, P. acnes and E. coli, including those from Punica granatum, and it was noted that the activity was higher with RJE than with RJW. Conclusions : These results provide evidence that ethanol extracts of Punica granatum and Rhus javanica may have a beneficial role as antioxidants and antibiotics. Extracts from domestic samples of Betula platyphylla var japonica appeared to have a greater efficacy than extracts from foreign samples.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.157.3-158
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• 2003

The antioxidant and anticancer properties of a medicinal plant, Betula platyphylla var. japonica were investigated. The total methanol extract of B. platyphylla var. japonica had protective effects against hydrogen peroxide ($H_2O_2$) in the Chinese hamster lung fibroblast (V79-4) cell line and induced apoptotic cell death in human promyelocytic leukemia (HL-60) cells, a cancer cell line. B. platyphylla var. japonica extract significantly increased cell viability against $H_2O_2$. The extract also showed high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity ($IC_50$ 2.4 mg/ml) and lipid peroxidation inhibitory activity ($IC_50$ below 4.0 mg/ml). (omitted)

• The Korean Journal of Ecology
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• 제26권4호
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• pp.165-172
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• 2003

The objectives of this study were to examine the physiological responses to ozone and to measure ozone uptake rates of Betula species exposed to relatively high concentration of pollutants. At the end of the growing season, photosynthesis, pigments contents, antioxidants (SOD and GR) and ozone uptake rates were measured or estimated at the leaves of five Betula species (Betula costata, B. davurica, B. platyphylla var. japonica, B. schmidtii and B. ermanii) exposed to 100ppb ozone concentration. On the termination of the experiment, growth effects were determined by measuring leaf area and dry weights of leaf, stem and root. Ozone treatment showed the significant reduction the leaf area and dry weight of four Betula species, except for B. ermanii. Shoot / root (SR) ratio of five species represented two different types. SR ratio of B. costata and B. davurica were lower than control, in contrast, SR ratio of B. platyphylla var. japonica, B. schimidtii and B. emani, were higher than that of control. The photosynthetic responses of five species were different in responses to ozone exposure. Four species, except for B. emanii, maintained or increased the stomatal conductance, but B. emanii decreased both stomatal conductance and photosynthesis. SOD activities of five species decreased by the ozone exposure, especially B. ermanii showed the largest reduction, GR activities of B. platyphylla var. japonica and B. schmidtii increased, B. costata and B. emanii decreased. Instantaneous ozone uptake rate was the highest at the leaves of B. ermanii and B. costata, ozone uptake per seedling was the highest at the leaf of B. schmidtii and B. emanii. It was concluded that B. costata, B. davurica and B. platyphylla var. japonica, appeared the growth reduction and visible ozone injury, were sensitive species to ozone, and B. schmidtii with the increased antioxidant activity and B. ermanii without the growth reduction were relatively resistant species to high ozone concentration at the early growing stage.

• 한국산림과학회지
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• 제95권5호
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• pp.614-620
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• 2006

To study the chlorophyll contents and photosynthetic characteristics of 4 tree species of deciduous hardwoods; Betula platyphylla var. japonica, Zelkova serrata, Acer mono and Prunus sargentii were treated in 3 stages of shading; the full sun treatment, the medium shade treatment with 30% of transmittance comparing to full sun, the intense shade treatment with 8% of transmittance and their changes in chlorophyll contents and photosynthetic characteristics were examined and analyzed. Most hardwoods showed differences in the total chlorophyll contents in the order of May < September < July, however, that in Prunus sargentii increased progressively along with the lapse of time. Concerning the degree of shading, total chlorophyll contents increased in proportion to the level of shading. Betula platyphylla var. japonica and Prunus sargentii showed more than 2-3 times difference between the full sun treatment and the intense shade treatment. The changes in photosynthetic characteristics, the range of the light saturation point of the trees was $1,000{\sim}1,100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in May, before the shading was applied, and the intensity was shown in the order of Betula platyphylla var. japonica > Zelkova serrata > Acer mono > Prunus sargentii. The photosynthetic rate was $6.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}{\sim}27.1{\mu}mol{\cdot}CO_2{\cdot}m^{-2}{\cdot}s^{-1}$ in the order of Betula platyphylla var. japonica > Prunus sargentii > Acer mono > Zelkova serrata that there were differences between species. Concerning the changes in light saturation point in each growth period after shading treatment, the light saturation point in the full sun treatment was found in the range of $560{\sim}1,100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and the level of intensity was shown in the order of May > July > September. The light saturation point decreased as the level of shading intensified and the level of changes in light compensation point in the full sun treatment for Betula platyphylla var. japonica and Prunus sargentii was shown in the range of $2.9{\sim}27.1{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in the order of May > July > September, however, for Zelkova serrata and Acer mono was shown in the range of $3.9{\sim}11.7{\mu}mol{\cdot}CO_2{\cdot}m^{-2}{\cdot}s^{-1}$ in the order of July > May > September that there were differences between species.

• Natural Product Sciences
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• 제24권4호
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• pp.235-240
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• 2018

Betula platyphylla var. japonica (Betulaceae), also known as Asian white birch, is an endemic medicinal tree, the bark of which has been used in Chinese traditional medicine for the treatment of various inflammatory diseases. In our continuing search for bioactive compounds from Korean natural resources, a phytochemical investigation of the bark of B. platyphylla var. japonica led to the isolation of 7-oxo-${\beta}$-sitosterol (1) and soyacerebroside I (2) from its ethanol extract as main components by liquid chromatography (LC)/mass spectrometry (MS)-based analysis. The structures of isolates were identified by comparison of $^1H$ and $^{13}C$ nuclear magnetic resonance spectroscopic data and physical data with the previously reported values and LC/MS analyses. To the best of our knowledge, this is the first study to demonstrate that the isolated compounds, 7-oxo-${\beta}$-sitosterol and soyacerebroside I, were isolated in B. platyphylla var. japonica. We examined the effects of the isolates on the regulation of adipocytes and osteoblast differentiation. These isolates (1 and 2) produced fewer lipid droplets compared to the untreated negative control in Oil Red O staining of the mouse mesenchymal stem cell line without altering the amount of alkaline phosphatase staining. The results demonstrated that both compounds showed marginal inhibitory effects on adipocyte differentiation but did not affect osteoblast differentiation.

• Journal of the Korean Wood Science and Technology
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• 제17권1호
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• pp.55-68
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• 1989

This experiment was carried out to investigate the crack of coated Nitrocellulose Lacquer on flatand edge-grained boards of Quercus acutissima, ring-porous wood, and Betula platyphylla var. japonica, diffuse-porous wood, by variations of moisture contents at 7, 13 and 21%. Cold check system was used as an accelerating method for crack development, in which one cycle of the system consisted of 10 replications of each unit cycle, $60^{\circ}C$ for 4hr followdd by $-20^{\circ}C$ for 4hr. The analysis of Nitrocellulose Lacquer characteristics was made by means of water permeation measurement, F.T.I.R. spectroscopy, N.M.R. spectroscopy, gel permeation chromatography, gas chromatography, and D.S.C. The results obtained were as follows: 1. The number of cracks increased with the increasing moisture content of board. 2. The crack of coated film on flat-grained board was fewer in number than on edge-grained board. 3. The crack occurred in Quercus acutissima was more numerous on edge-grained board but less frequent on flat-grained board compared with that in Betula platyphylla var. japonica, respectively. 4. The cold crack vertically developed to the grain both in Quercus acutissima and Betula platyphylla var. japonica. 5. Water permeability in intermediate coated film was lower than in under and top coated film, but the difference was not confirmed between under and top coated film.