• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.30-30
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• 2022

Natural products decursin and decursinol angelate were recently reported as benign fungicides for controlling rice blast. Inspired by the structural similarity of the cumarin compounds and gained hint from the skeletal motifs, we designed and prepared synthetic compounds to increase the natural product efficacy and evaluated their antifungal activities against various plant disease pathogens in vitro. Synthetically prepared compound 4 and 5 indeed suppressed the mycelial growth of B. cinerea, F. oxysporum, P. italicum, and R. quercus-mongolicae. Additionally, compound 5 effectively prevents the growth of C. coccodes and C. parasitica. Furthermore, both 4 and 5 possess better inhibitory activities on spore germination of F. oxysporum and M. oryzae than the natural product decursin. These results suggest that the effect of the lead compound for plant disease protection can be improved by tuning the structure of the original natural product and decursinol chloroacrylates 4 and 5 are candidates for the control of F. oxysporum and M. oryzae.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.98-98
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• 2022

Natural products decursin and decursinol angelate were recently reported as benign fungicides for controlling rice blast. Inspired by the structural similarity of the cumarin compounds and gained hint from the skeletal motifs, we designed and prepared synthetic compounds to increase the natural product efficacy and evaluated their antifungal activities against various plant disease pathogens in vitro. Synthetically prepared compound 4 and 5 indeed suppressed the mycelial growth of B. cinerea, F. oxysporum, P. italicum, and R. quercus-mongolicae. Additionally, compound 5 effectively prevents the growth of C. coccodes and C. parasitica. Furthermore, both 4 and 5 possess better inhibitory activities on spore germination of F. oxysporum and M. oryzae than the natural product decursin. These results suggest that the effect of the lead compound for plant disease protection can be improved by tuning the structure of the original natural product and decursinol chloroacrylates 4 and 5 are candidates for the control of F. oxysporum and M. oryzae.

• Natural Product Sciences
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• v.20 no.2
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• pp.80-85
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• 2014

In the course of screening for antioxidant compounds from natural plants in Korea by measuring the radical scavenging effect, a methanol extract of the flower buds of Daphne genkwa S. et Z. (Thymelaeaceae) was found to show a potent antioxidant activity. Subsequent activity-guided fractionation of methanol extract of D. genkwa led to the isolation of four compounds from the ethyl acetate soluble fraction. The chemical structures were elucidated as genkwanin (1), 3'-hydroxygenkwanin (2), apigenin (3), and tiliroside (4) by spectroscopic techniques. Among them, compound 2 showed the significant anti-oxidative effect on DPPH. And compound 2 showed the significant riboflavin-and xanthine-originated superoxide quenching activities. To verify the antioxidant enzymatic activities of compound 2, the SOD enzymatic activity was measured spectrophtometrically using prepared Caenorhabditis elegans homogenates. The results showed that compound 2 was able to elevate SOD activity of C. elegans in a dose dependent manner. Moreover, compound 2 decreased the intracellular ROS accumulation of worms.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1282-1284
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• 2006

In the course of search for hepatoprotective agents from oriental traditional medicines, one compound was isolated from the MeOH extract of the fruits of Schizandra chinensis, and its structure was determined as gomisin J(1). The evaluation for hepatoprotective activity of isolated compound 1 on drug-induced cytotoxicity was conducted, and compound 1 showed protective effect with an EC$_{50}$value of 86.0 ${\pm}$ 5.3 ${\mu}$M against tacrine-induced cytotoxicity in Hep G2 cells. One of the well-known hepatoprotective agents, silybin, used as a positive control, and the hepatoprotective effect of compound 1 is similar with that of silybin (EC$_{50}$ value = 90.5 ${\pm}$ 9.8 ${\mu}$M).

• Natural Product Sciences
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• v.10 no.6
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• pp.347-352
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• 2004

When saponin extracts of dried ginseng and red ginseng were anaerobically incubated with human intestinal microflora, these extracts were metabolized to compound K and ginsenoside $Rh_2$, respectively. However, when these extracts were incubated with commercial lactic acid bacteria, these did not metabolize these ginsenosides to compound K or ginsenoside $Rh_2$. Among some intestinal bacteria isolated from human feces, Bacteroides C-35 and C-36 transformed these saponin extracts to compound K and ginsenoside $Rh_2$, respectively. These bacteria also transformed water extracts of dried ginseng and red ginseng to compound K and ginsenoside $Rh_2$, respectively, similarly with that of the saponin extracts. Among transformed ginsenosides, compound K and 20(S)-ginsenoside $Rh_2$ exhibited the most potent cyotoxicity against tumor cells.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.995-1003
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• 2021

Coastal compound disasters are becoming more extreme and more frequent due to climate change. Thus, appropriate and systematic disaster management is necessary to reduce potential losses. One solution to this is the creation of a coastal compound disaster management area. However, Korea's "Countermeasures against Natural Disasters Act" needs to be reformed to introduce this coastal compound disaster management area. In this study, we tried to find the appropriate direction for reforming the Act in order to establish a basis for implementing regulations on the Coastal Compound Disaster Management Area with regard to three aspects: science-based management, cooperative management, and adaptive management. The study was on the premise that the system would be operated based on the provisions of the "Countermeasures against Natural Disasters Act". Consequently for effective science-based management, it is necessary to introduce a disaster risk assessment framework. Based on the results obtained through the implementation of this framework, the management areas should be set with differential measures. Next, cooperation among the various ministries is essential to successfully respond to disasters. This study recommends the establishment of an advisory council composed of the related government departments as a pragmatic solution. Finally, in terms of adaptive management, we found that parallelly utilizing non-structural measures could compensate for the limitations of structural measures.

• Natural Product Sciences
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• v.17 no.1
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• pp.10-13
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• 2011

As parts of our continuing search for biologically active compounds from medicinal plants, we investigated the constituents of the seeds of Amomum xanthioides and isolated a sesquiterpenoid, a nerolidol derivative from its MeOH extract. The chemical structure was determined by spectroscopic methods, including 1D and 2D NMR to be ($2S^*$,$2'R^*$,$5'S^*$)-2-(5'-ethenyltetrahydro-5'-methylfuran-2'-yl)-6-methylhept-5en-2-ol (1). Compound 1 was isolated for the first time from nature source. Compound 1 exhibited a good cytotoxicity against SK-OV-3 and SK-MEL-2 cells ($IC_{50}$: 16.7 and $8.6\;{\mu}M$, respectively) using a SRB bioassay. In this study, we also determined the absolute configuration of 2 reported in previous paper.

• Natural Product Sciences
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• v.16 no.1
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• pp.6-9
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• 2010

In continuing our search for biologically active compounds from Korean Compositae medicinal plants, we investigated the constituents of the aerial parts of Lactuca indica L. and isolated a phenylpropanoid derivative from its MeOH extract. The chemical structure was characterized by spectroscopic methods, including 1D and 2D NMR to be di-E-caffeoyl-meso-tartaric acid (1). Compound 1 was isolated for the first time from this plant. In this paper, we suggest that the NMR assignment at C-2 of (+)-taraxafolin-B should be corrected. In the human HBV-transfected liver cell line HepG2.2.15, the compound 1 effectively reduced HBV DNA level in the release of mature HBV particles from HepG2.2.15 cultivation.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.193.3-194
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• 2003

Platelets play critical roles in both hemostasis and thrombosis. It was reported that platelet aggregation is associated with an increase in superoxide production and can be inhibited by hydroxyl radical scavengers. In the course of our search for the anti-platelet, anti-coagulant and/or anti-oxidative components from plants, the MeOH extract of Crassula cv. "Himaturi" (Crassulaceae) was observed to have both anti-aggregatory and anti-coagulant effects. A novel compound, 12-O-(4'-O-methyl-galloyl)-bergenin (1), was isolated as an active component from the EtOAC soluble fraction. (omitted)

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1505-1508
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• 2012

Protein tyrosine phosphatase 1B (PTP1B) is a key factor in negative regulation of the insulin pathway, and is a promising target for the treatment of type-II diabetes, obesity and cancer. Herein, compound ($\mathbf{4}$) was first observed to have moderate inhibitory activity against PTP1B with an $IC_{50}$ value of $13.72{\pm}1.53{\mu}M$. To obtain more potent PTP1B inhibitors, we synthesized a series of chalcone derivatives using compound ($\mathbf{4}$) as the lead compound. Compound $\mathbf{4l}$ ($IC_{50}=3.12{\pm}0.18{\mu}M$) was 4.4-fold more potent than the lead compound $\mathbf{4}$ ($IC_{50}=13.72{\pm}1.53{\mu}M$), and more potent than the positive control, ursolic acid ($IC_{50}=3.40{\pm}0.21{\mu}M$). These results may help to provide suitable drug-like lead compounds for the design of inhibitors of PTP1B as well as other PTPs.