• Mass Spectrometry Letters
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• v.7 no.2
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• pp.45-49
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• 2016

An UHPLC-ESI-qTOF-MS analytical method was developed for cyclopeptide alkaloids in the seeds of Ziziphus jujuba var. spinosa (Semen Ziziphi Spinosae), which is a commonly used herb in Chinese and Korean traditional medicines. Considering the basicity of cyclopeptide alkaloids, a specific separation method was developed for an UHPLC system. The compounds were detected by DAD and ESI-qTOF-MS, and their fragmentation patterns were also acquired by MS^E technologies. Peak-picking of major compounds was performed with nine previously isolated compounds and two reference standard compounds. Tandem MS fragmentation behaviors of type-Ia and -Ib cyclopeptide alkaloids were investigated with the acquired data to develop a strategy for dereplication of other cyclopeptide alkaloid compounds in Z. jujuba var. spinosa. Two more cyclopeptide alkaloids were tentatively identified with UHPLC-ESI-qTOF-MS using this method.

• Journal of Applied Biological Chemistry
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• v.58 no.2
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• pp.175-181
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• 2015

Compositions of essential oils extracted from mint herb such as Mentha piperita, Mentha spicata, and Mentha ${\times}$ piperita var. citrate produced in Jeju were analyzed using gas chromatography-mass spectrometry (GC-MS) and headspace-GC-MS (HS-GC-MS). By the GC-MS analysis, 13 compounds were tentatively identified in Mentha piperita, Mentha spicata, and Mentha ${\times}$ piperita var. citrate, respectively. Peperitenone oxide, carvone, and linalool were detected as major compounds in Mentha piperita, in Mentha spicata, in Mentha ${\times}$ piperita var. citrate, respectively, based on the ratio of peak intensity in the total ion chromatogram. The greater number of compounds, including volatile alcohols and acetates were identified by HS-GC-MsS than by GC-MS in these all three essential oils. Similar patterns of composition were detected in both Mentha spicata and Mentha ${\times}$ piperita var. citrate by either one of GC-MS methods. However, in case of Mentha piperita, $\small{L}$-(-)-menthol, which was identified as the major compound by HS-GC-MS was detected in dramatically reduced quantity by GC-MS. Interestingly, we found that both linalyl acetate and linalool were identified as the dominant compounds in the essential oil of Mentha ${\times}$ piperita var. citrate.

• Management & Information Systems Review
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• v.35 no.3
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• pp.1-22
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• 2016

We analyzed the international comovements and structural changes in the quarterly real GDP by the Markov-switching vector autoregressive model (MS-VAR) from 1971(1) to 2016(1). The main results of this study were as follows. First, the business cycle phenomenon that occurs in the models or individual time series in real GDP has been grasped through the MS-VAR models. Unlike previous studies, this study showed the significant comovements, asymmetry and structural changes in the MS-VAR model using a real GDP across countries. Second, even if there was a partial difference, there were remarkable structural changes in the economy contraction regime(recession), such as 1988(2) ending the global oil shock crisis and 2007(3) starting the global financial crisis by the MS-VAR model. Third, large-scale structural changes were generated in the economic expansion and/or contraction regime simultaneously among countries. We found that the second world oil shocks that occurred after the first global oil shocks of 1973 and 1974 were the main reasons that caused the large-scale comovements of the international real GDP among countries. In addition, the spillover between Korea and 5 countries has been weak during the Asian currency crisis from 1997 to 1999, but there was strong transmission between Korea and 5 countries at the end of 2007 including the period of the global financial crisis. Fourth, it showed characteristics that simultaneous correlation appeared to be high due to the country-specific shocks generated for each country with the regime switching using real GDP since 1973. Thus, we confirmed that conclusions were consistent with a number of theoretical and empirical evidence available, and the macro-economic changes were mainly caused by the global shocks for the past 30 years. This study found that the global business cycles were due to large-scale asymmetric shocks in addition to the general changes, and then showed the main international comovements and/or structural changes through country-specific shocks.

• Korean Journal of Plant Resources
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• v.6 no.2
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• pp.171-179
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• 1993

This study was conducted to investigate the effect of growth regulators and medium composition on the growth of each stage in apical meristem culture for mass propagation of Zanthoxylum piperitum var. inerme Makino. The source material, shoot tip segments were taken from three-years old graft trees. Apical meristems were cultured in vitro on basal MS, GD, WS, half strength MS(1/2MS) and half strength GD(1/2GD) media supplemented with various concentrations for growth regulators(BA, IBA) and inorganic nutrients. The results summarized are as follows: 1. In culture establishment stage, ratio of culture establishment was 96.7% and the best resuit was obtained using MS medium supplemented with 1.0mg/l BA and 0.2mg/l IBA. 2. In shoot multitication stage, both shoot multiplication and growth were achieved in average 5.6cm. These results were obtained on in MS medium supplemented with 1.0mg/l BA and 0.2mg/l IBA. 3. In roothing stage, phloroglucinol(PG) acted as IBA synergist in root initiation. The most faverable combinations for root development was half-strength MS medium supplemented with 162mg/l PG and 0.2mg/l IBA, and ratio of rooting was 58.0%. 4. In Vitro formed plantlets were transplanted to paper pots in greenhouse with 85% of relative humidity. 96% of survival rate was obtained from artificial soil mix having same volume of sand, vermiculite, peat, and soil.

• Korean Journal of Pharmacognosy
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• v.19 no.3
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• pp.181-187
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• 1988

$Two\;C_{19}-diterpene\;alkaloids$ were isolated from the root of Aconitum psedolaeve var. erectum Nakai, and identified as lycoctonine and septentriodine by UV, IR, MS and NMR data.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.568-572
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• 2010

In order to develop an efficient micropropagation system for a rare tree species, Empetrum nigrum var. japonicum K. Koch, the effect of medium salt, cytokinins and auxin at different concentration were evaluated. Shoot induction from axillary bud was better on WPM medium than on MS medium. Although there was no significant differences observed in shoot induction among the salt strengths of WPM medium, whereas healthy shoots were developed on basal WPM medium. In comparison of the cytokinins affecting shoot proliferation, zeatin was better than BA, whereas BA exhibited more effectiveness on shoot elongation. In vitro root formation was better on WPM medium than on 1/2MS medium and achieved the highest rooting rate when 5.0 mg/L IBA treatment. 93% of rooted plantlets were survived on artificial soil mixture after 4 weeks of acclimatization. Above results suggest that a rare tree species, E. nigrum var. japonicum can be micropropagated via axillary bud cultures.

• Natural Product Sciences
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• v.24 no.4
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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.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.432-435
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• 2006

A rapid and mass propagation method for multiple shoots and plant regeneration using bulb scales of Muscari comosum var. plumosum were developed. In vitro different parts of bulb scale as explants were cultured on 11 kinds of MS (1962) media supplemented with various plant growth regulators to induce shoot and callus. A combination of 2.0 mg/L 6-BA and 2.0 mg/L IBA on MS medium was the most favorable and induced the highest production (80%) of shoot formation after 30 days. We also found that the middle part of bulb scale was the best for mass propagation of Muscari comosum var. plumosum of which production could reach 64.4%.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.448-453
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• 2017

This study was carried out to find culture materials (explant parts) and medium components (medium type, sucrose and $NaH_2PO_4$ concentration) for in vitro propagation of Osmunda cinnamomea var. forkiensis sporophyte. The results of study: chopped segments of leaf blades, stipes, rhizomes and roots were cultured on a 1/2MS medium supplemented with 0.1% activated charcoal. Among these explant types, only the rhizome segments produced young sporophyte, regenerating vigorously on a 1/8MS medium. Adjusting the sucrose concentration to 2% and supplement to $50mg{\cdot}L^{-1}\;NaH_2PO_4$ in the 1/8MS medium proved to be more efficient for plant regeneration. Consequently, the addition of 0.1% activated charcoal to a modified 1/8MS medium (2% sucrose, $50mg{\cdot}L^{-1}\;NaH_2PO_4$, pH 5.8 and 0.8% agar) yielded the highest sporophyte regeneration.

• Korean journal of food and cookery science
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• v.16 no.3
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• pp.221-225
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• 2000

This study was conducted to investigate the usefulness of Perilla frutescens var. acuta as a natural spice. Volatile flavor components of dried Perilla frutescens var. acuta were extracted by supercritical fluid extraction method using diethyl ether as solvent. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). Identification of volatile flavor components was based on the RI of GC and mass spectrum of GC-MS. A total of 24 components, including 4 hydrocarbons, 3 aldehydes, 8 alcohols, 4 esters, 3 acids and 2 miscellaneous components were identified in the essential oils. L-Perillaldehyde was found to be the major volatile flavor component of dried Perilla frutescens var. acuta. The masking effects of Perilla frutescens var. acuta on meaty and fishy flavor were measured by sensory evaluation. Meaty flavor was significantly reduced with the addition of 0.05%, 0.1%, and 0.2% Perilla frutescens var. acuta. The addition of 0.1% and 0.2% powdered Perilla frutescens var. acuta also reduced the fishy flavor of mackerel.