Publications by authors named "Jaeyoung Kwon"

26 Publications

  • Page 1 of 1

Natural photosensitizers from Tripterygium wilfordii and their antimicrobial photodynamic therapeutic effects in a Caenorhabditis elegans model.

J Photochem Photobiol B 2021 May 29;218:112184. Epub 2021 Mar 29.

Natural Product Informatics Research Center, Gangneung Institute of Natural Products, Korea Institute of Science and Technology, Gangwon-do 25451, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology (UST), Gangneung, Gangwon-do 25451, Republic of Korea. Electronic address:

Tripterygium wilfordii Hook. f. is a traditional medicinal plant and has long been used in East Asia to treat many diseases. However, the extract and active components have never been investigated as potential photosensitizers for photodynamic treatment to kill pathogenic microorganisms. Here, the antimicrobial photodynamic treatment (APDT) effects of the extract, fractions, and compounds of T. wilfordii were evaluated in vitro and in vivo. Ethanolic extract (TWE) and the photosensitizer-enriched fraction (TW-F5) were prepared from dried T. wilfordii. Six active compounds were isolated from TW-F5 by semipreparative high-performance liquid chromatography, and their chemical structures were characterized through spectroscopic and spectrometric analysis. The singlet oxygen from extracts, fractions, and compounds was measured by using the imidazole-N,N-dimethyl-4-nitrosoaniline method. These extracts, fractions, and compounds were used as photosensitizers for the inactivation of bacteria and fungi by red light at 660 nm. The in vitro APDT effects were also evaluated in the model animal Caenorhabditis elegans. APDT with TWE showed effective antimicrobial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans. TW-F5, consisting of six pheophorbide compounds, also showed strong APDT activity. The photosensitizers were taken up into the bacterial cells and induced intracellular ROS production by APDT. TWE and TW-F5 also induced a strong APDT effect in vitro against skin pathogens, including Staphylococcus epidermidis and Streptococcus pyogenes. We evaluated the APDT effects of TWE and TW-F5 in C. elegans infected with various pathogens and found that PDT effectively controlled pathogenic bacteria without strong side effects. APDT reversed the growth retardation of worms induced by pathogen infection and decreased the viable pathogenic bacterial numbers associated with C. elegans. Finally, APDT with TWE increased the survivability of C. elegans infected with S. pyogenes. In summary, TWE and TW-F5 were found to be effective antimicrobial photosensitizers in PDT.
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http://dx.doi.org/10.1016/j.jphotobiol.2021.112184DOI Listing
May 2021

Mimicking the Mechanical Properties of Aortic Tissue with Pattern-Embedded 3D Printing for a Realistic Phantom.

Materials (Basel) 2020 Nov 9;13(21). Epub 2020 Nov 9.

Department of Convergence Medicine, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap2-dong, Songpa-gu, Seoul 138-828, Korea.

3D printing technology has been extensively applied in the medical field, but the ability to replicate tissues that experience significant loads and undergo substantial deformation, such as the aorta, remains elusive. Therefore, this study proposed a method to imitate the mechanical characteristics of the aortic wall by 3D printing embedded patterns and combining two materials with different physical properties. First, we determined the mechanical properties of the selected base materials (Agilus and Dragonskin 30) and pattern materials (VeroCyan and TPU 95A) and performed tensile testing. Three patterns were designed and embedded in printed Agilus-VeroCyan and Dragonskin 30-TPU 95A specimens. Tensile tests were then performed on the printed specimens, and the stress-strain curves were evaluated. The samples with one of the two tested orthotropic patterns exceeded the tensile strength and strain properties of a human aorta. Specifically, a tensile strength of 2.15 ± 0.15 MPa and strain at breaking of 3.18 ± 0.05 mm/mm were measured in the study; the human aorta is considered to have tensile strength and strain at breaking of 2.0-3.0 MPa and 2.0-2.3 mm/mm, respectively. These findings indicate the potential for developing more representative aortic phantoms based on the approach in this study.
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http://dx.doi.org/10.3390/ma13215042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7664885PMC
November 2020

Inhibitory Effect of Cudratrixanthone U on RANKL-Induced Osteoclast Differentiation and Function in Macrophages and BMM Cells.

Front Pharmacol 2020 5;11:1048. Epub 2020 Aug 5.

College of Pharmacy, Keimyung University, Daegu, South Korea.

Cudratrixanthone U (CTU) is a prenylated xanthone compound isolated from Bureau (Moraceae). Prenylated xanthones have been reported to exhibit a variety of biological activities. However, the effects of prenylated xanthone on osteoclast differentiation and function are still unclear. Excessive bone resorption by osteoclasts is considered a major cause of diseases such as osteoporosis. Accordingly, suppression of excessive osteoclast formation and function is one of strategies for treating osteoclast related bone diseases. In this study, CTU inhibited osteoclast differentiation and function in RAW264.7 macrophages and BMM cells induced by receptor activator of nuclear factor-κB ligand (RANKL). CTU regulated the formation of TRAF6-TAK1 complex in RANKL-induced RAW264.7 macrophages and BMM cells. Osteoclast-specific genes including those encoding matrix metallopeptidase 9 (MMP-9), dendritic cell-specific transmembrane proteins (DC-STAMP), cathepsin K (CTSK) and chemokine CC motif ligand 4 (CCL4) play an important role in bone resorption and migration, and were effectively regulated by CTU. These results suggest that CTU is a potential therapeutic agent in osteoporosis.
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http://dx.doi.org/10.3389/fphar.2020.01048DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7419678PMC
August 2020

Constituents of and Their Neuroprotective Effects in HT22 Hippocampal Neuronal, R28 Retinal Cells, and BV2 Microglial Cells.

Plants (Basel) 2020 Aug 18;9(8). Epub 2020 Aug 18.

KIST Gangneung Institute of Natural Products, Korea Institute of Science and Technology (KIST), Gangneung 25451, Korea.

is widely used in traditional medicine and contains various types of metabolites with pharmacological activity. In the course of searching for neuroprotective molecules associated with the potential of in the treatment of neurodegenerative disorders, two new phenolic compounds ( and ) and a new tripeptide (), together with 16 known compounds (-), were isolated from the rhizomes of . The structures of the compounds were determined by the interpretation of spectroscopic data, including nuclear magnetic resonance and mass spectrometry data. All obtained compounds were assessed for their ability to protect neuronal cells against neurotoxicity and neuroinflammation. Of these, and were found to possess moderate activities in HT22 hippocampal neuronal cells, whereas , , and showed weak activities in R28 retinal cells. Additionally, compound showed moderate inhibitory activity on lipopolysaccharide-induced nitric oxide production in BV2 microglial cells.
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http://dx.doi.org/10.3390/plants9081051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7465223PMC
August 2020

Anti-inflammatory Metabolites from .

J Nat Prod 2020 04 12;83(4):881-887. Epub 2020 Mar 12.

Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea.

Twelve metabolites were obtained from the culture media of , including a new furan derivative, methyl succinyl Sumiki's acid (), and two new atropisomers of the previously reported bis-naphtho-γ-pyrones, (a)-asperpyrone A and (a)-fonsecinone A ( and ). The structures were elucidated by spectroscopic, chemical, and chiroptical techniques. Compounds and inhibited nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages. Compound was found to inhibit nuclear factor-kappa B and c-Jun N-terminal kinase activation, in turn suppressing pro-inflammatory mediators and cytokines including nitric oxide, prostaglandin E, interleukin (IL)-1β, tumor necrosis factor-α, IL-6, and IL-12.
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http://dx.doi.org/10.1021/acs.jnatprod.9b00560DOI Listing
April 2020

Inhibition of the type III secretion system of Pseudomonas syringae pv. tomato DC3000 by resveratrol oligomers identified in Vitis vinifera L.

Pest Manag Sci 2020 Jul 11;76(7):2294-2303. Epub 2020 Feb 11.

Department of Biosystems and Biotechnology, Korea University Graduate School, Seoul, Republic of Korea.

Background: The bacterial type III secretion system (T3SS) is one of the virulence determinants of Gram-negative bacteria through which various effector and virulence proteins are translocated into host cells.

Results: We constructed an assay system to screen inhibitors of hrpA gene expression (a structural gene of Hrp pili) in Pseudomonas syringae pv. tomato DC3000. In a plant extract library screening, the root extract of Vitis vinifera L. displayed the most prominent activity. Three resveratrol oligomers, hopeaphenol, isohopeaphenol and ampelopsin A, were identified in grapevine root extract, which significantly reduced the transcription levels of the hrpA, hrpL and hopP1 genes without growth retardation. Additional resveratrol derivatives identified in other plant extracts were also examined for their inhibitory effect on hrpA expression. Another resveratrol oligomer, kobophenol A, also inhibited the transcription of the hrpA gene and other T3SS-related genes, while resveratrol monomers (resveratrol and piceatannol) were not effective. The severity of bacterial specks was reduced by each hopeaphenol, isohopeaphenol and ampelopsin A treatment.

Conclusion: These results show the potential of resveratrol derivatives as anti-virulence agents for the control of plant diseases.
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http://dx.doi.org/10.1002/ps.5764DOI Listing
July 2020

An Autophagy Inducing Triterpene Saponin Derived from .

Molecules 2019 Dec 7;24(24). Epub 2019 Dec 7.

Natural Product Informatics Research Center, Korea Institute of Science and Technology (KIST) Gangneung Institute, Gangneung 25451, Korea.

Autophagy is an important self-degradative mechanism that plays a key role in treating neurodegeneration diseases. This research aimed at discovering bioactive compounds from . A new triterpene saponin, astersaponin I (), was isolated from the EtOH extract of . The structure of 1 was characterized by spectroscopic methods, ECD calculation, and acid hydrolysis. The biochemical analysis showed that compound significantly increased the expression of microtubule-associated protein 1A/1B light chain 3B (LC3-II) expression in SH-SY5Y cells, which indicates the induction of autophagy. Thus, further study may be needed to clarify whether compound exerts beneficial effects on neurodegeneration diseases like Parkinson's disease through autophagy induction.
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http://dx.doi.org/10.3390/molecules24244489DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6943805PMC
December 2019

-Derived Drimane Sesquiterpenoids That Inhibit Osteoclast Differentiation.

J Nat Prod 2019 10 10;82(10):2835-2841. Epub 2019 Oct 10.

Laboratory Animal Resource Center , Korea Research Institute of Bioscience and Biotechnology , Cheongju 28116 , Republic of Korea.

The presence of excessive osteoclasts is a major factor in skeletal diseases. The present study aimed to discover osteoclast differentiation inhibitors from the basidiomycete . Seven new drimane sesquiterpenoids (-) and 7-ketoisodrimenin-5-ene () were obtained and characterized by various spectroscopic methods. The isolated compounds were evaluated for their inhibitory effects against receptor activator of nuclear factor-kappa-B ligand-induced osteoclastogenesis in mouse bone marrow macrophages. Compounds , , and showed potent activities with IC values of 1.6, 0.9, and 2.1 μM, respectively, while , , and exhibited relatively weak activities with IC values of 10.7, 10.1, and 8.5 μM, respectively.
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http://dx.doi.org/10.1021/acs.jnatprod.9b00559DOI Listing
October 2019

Enantiomeric Isoflavones with neuroprotective activities from the Fruits of Maclura tricuspidata.

Sci Rep 2019 02 11;9(1):1757. Epub 2019 Feb 11.

Department of Biosystems and Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul, 02841, Republic of Korea.

Seven pairs of enantiomeric isoflavones (1a/1b-7a/7b) were obtained from the ethyl acetate extract of the fruits of Maclura tricuspidata (syn. Cudrania tricuspidata), and successfully separated by chiral high-pressure liquid chromatography (HPLC). The structures and absolute configurations of the enantiomeric isoflavones were established on the basic of comprehensive spectroscopic analyses and quantum chemical calculation methods. Compounds 1, 1a, and 1b exhibited neuroprotective activities against oxygen-glucose deprivation/reoxygenation (ODG/R)-induced SH-SY5Y cells death with EC values of 5.5 µM, 4.0 µM, and 10.0 µM, respectively. Furthermore, 1, 1a, and 1b inhibited OGD/R-induced reactive oxygen species generation in SH-5Y5Y cells with IC values of 6.9 µM, 4.5 µM, and 9.5 µM, respectively.
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http://dx.doi.org/10.1038/s41598-018-36095-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6370789PMC
February 2019

Generation of customized orbital implant templates using 3-dimensional printing for orbital wall reconstruction.

Eye (Lond) 2018 12 28;32(12):1864-1870. Epub 2018 Aug 28.

Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Objectives: To describe and evaluate a novel surgical approach to orbital wall reconstruction that uses three-dimensionally (3D) printed templates to mold a customized orbital implant.

Methods: A review was conducted of 11 consecutive patients who underwent orbital wall reconstruction using 3D-printed customized orbital implant templates. In these procedures, the orbital implant was 3D pressed during surgery and inserted into the fracture site. The outcomes of this approach were analyzed quantitatively by measuring the orbital tissue volumes within the bony orbit using computed tomography.

Results: All 11 orbital wall reconstructions (6 orbital floor and 5 medial wall fractures) were successful with no post operative ophthalmic complications. Statistically significant differences were found between the preoperative and post operative orbital tissue volumes for the affected orbit (24.00 ± 1.74 vs 22.31 ± 1.90 cm; P = 0.003). There was no statistically significant difference found between the tissue volume of the contralateral unaffected orbit and the affected orbit after reconstruction (22.01 ± 1.60 cm vs 22.31 ± 1.90 cm; P = 0.182).

Conclusion: 3D-printed customized orbital implant templates can be used to press and trim conventional implantable materials with patient-specific contours and sizes for optimal orbital wall reconstruction. It is difficult to design an orbital implant that exactly matches the shape and surface of a blowout fracture site due to the unique 3D structure of the orbit. The traditional surgical method is to visually inspect the fracture site and use eye measurements to cut a two-dimensional orbital implant that corresponds to the anatomical structure of the fracture site. However, implants that do not fit the anatomical structure of a fracture site well can cause complications such as enophthalmos, diplopia and displacement of the implant.
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http://dx.doi.org/10.1038/s41433-018-0193-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6293000PMC
December 2018

Cytotoxic Drimane Sesquiterpenoids Isolated from Perenniporia maackiae.

J Nat Prod 2018 06 7;81(6):1444-1450. Epub 2018 Jun 7.

Laboratory Animal Resource Center , Korea Research Institute of Bioscience and Biotechnology , Cheongju 28116 , Republic of Korea.

A chemical investigation of a basidiomycetes fungus, Perenniporia maackiae, led to the discovery of 12 drimane sesquiterpenoids, including seven new constituents (1-7). The elucidation of the structures was performed via interpreting extensive spectroscopic methods, including ECD calculations. Among all isolated compounds, 1, 2, and 6 exhibited cytotoxicity toward six carcinoma cells, including ACHN, HCT-15, MDA-MB-231, NCI-H23, NUGC-3, and PC-3 cells, with half-maximal inhibition of cell proliferation values of 1.2-6.0 μM.
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http://dx.doi.org/10.1021/acs.jnatprod.8b00175DOI Listing
June 2018

Effect of processing method on platycodin D content in Platycodon grandiflorum roots.

Arch Pharm Res 2017 Sep 29;40(9):1087-1093. Epub 2017 Aug 29.

Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Korea.

Platycodon grandiflorum root is a traditional medicine and food material rich in triterpenoid saponins. Its major constituent, platycodin D (PD), is known to have various pharmacological properties, but processing methods may influence the PD content. In this study, a fully validated HPLC-ELSD method was developed for the quantification of PD in various states of 73 P. grandiflorum root samples from East Asia, and it exhibited a marked variation of the content. Furthermore, the effects of processing procedures such as peeling and drying temperature on the PD content were investigated using UPLC-ELSD analysis, and as a result, a significant influence of processing methods such as peeling and heating of samples on the content was confirmed. Specifically, unpeeled samples that were dried at 40 °C showed the greatest PD content. The obtained results could facilitate the reliable standardization of P. grandiflorum for precise authentication and efficacious applications.
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http://dx.doi.org/10.1007/s12272-017-0946-6DOI Listing
September 2017

Mulberrofuran G Protects Ischemic Injury-induced Cell Death via Inhibition of NOX4-mediated ROS Generation and ER Stress.

Phytother Res 2017 Feb 2;31(2):321-329. Epub 2016 Dec 2.

Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul, 08826, Korea.

The aim of this study was to investigate the neuroprotective effect of mulberrofuran G (MG) in in vitro and in vivo models of cerebral ischemia. MG was isolated from the root bark of Morus bombycis. MG inhibited nicotinamide adenine dinucleotide phosphate oxidase (NOX) enzyme activity and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced NOX4 protein expression in SH-SY5Y cells. MG inhibited the expression of activated caspase-3 and caspase-9 and cleaved poly adenine dinucleotide phosphate-ribose polymerase in OGD/R-induced SH-SY5Y cells. In addition, MG protected OGD/R-induced neuronal cell death and inhibited OGD/R-induced reactive oxygen species generation in SH-SY5Y cells. In in vivo model, MG-treated groups (0.2, 1, and 5 mg/kg) reduced the infarct volume in middle cerebral artery occlusion/reperfusion-induced ischemic rats. The MG-treated groups also reduced NOX4 protein expression in middle cerebral artery occlusion/reperfusion-induced ischemic rats. Furthermore, protein expression of 78-kDa glucose-regulated protein/binding immunoglobulin protein, phosphorylated IRE1α, X-box-binding protein 1, and cytosine enhancer binding protein homologous protein, mediators of endoplasmic reticulum stress, were inhibited in MG-treated groups. Taken together, MG showed protective effect in in vitro and in vivo models of cerebral ischemia through inhibition of NOX4-mediated reactive oxygen species generation and endoplasmic reticulum stress. This finding will give an insight that inhibition of NOX enzyme activity and NOX4 protein expression could be a new potential therapeutic strategy for cerebral ischemia. Copyright © 2016 John Wiley & Sons, Ltd.
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http://dx.doi.org/10.1002/ptr.5754DOI Listing
February 2017

Quassinoids isolated from Brucea javanica inhibit pepper mottle virus in pepper.

Virus Res 2017 01 26;227:49-56. Epub 2016 Sep 26.

Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea. Electronic address:

A green fluorescent protein (GFP)-tagged pepper mottle virus (PepMoV) based leaf-disc method and systemic host method were developed to identify antiviral agents. Preliminary experiments using a PepMoV-GFP based leaf-disc method led to the isolation of five quassinoids, including brusatol (1), bruceantin (2), brucein A (3), bruceantinol (4), and brucein B (5), from the CHOH extract of Brucea javanica. All isolated compounds exhibited inactivation effects in systemic host plants, and compounds 3 and 4 were potent, with a minimum inhibitory concentration of 10μM. Furthermore, compound 3 was found to have a protective effect at the tested concentration of 40μM.
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http://dx.doi.org/10.1016/j.virusres.2016.09.013DOI Listing
January 2017

Drastic anthocyanin increase in response to PAP1 overexpression in fls1 knockout mutant confers enhanced osmotic stress tolerance in Arabidopsis thaliana.

Plant Cell Rep 2016 Nov 25;35(11):2369-2379. Epub 2016 Aug 25.

Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea.

KEY MESSAGE : pap1 - D/fls1ko double mutant plants that produce substantial amounts of anthocyanin show tolerance to abiotic stress. Anthocyanins are flavonoids that are abundant in various plants and have beneficial effects on both plants and humans. Many genes in flavonoid biosynthetic pathways have been identified, including those in the MYB-bHLH-WD40 (MBW) complex. The MYB gene Production of Anthocyanin Pigment 1 (PAP1) plays a particularly important role in anthocyanin accumulation. PAP1 expression in many plant systems strongly increases anthocyanin levels, resulting in a dark purple color in many plant organs. In this study, we generated double mutant plants that harbor fls1ko in the pap1-D background (i.e., pap1-D/fls1ko plants), to examine whether anthocyanins can be further enhanced by blocking flavonol biosynthesis under PAP1 overexpression. We also wanted to examine whether the increased anthocyanin levels contribute to defense against osmotic stresses. The pap1-D/fls1ko mutants accumulated higher anthocyanin levels than pap1-D plants in both control and sucrose-treated conditions. However, flavonoid biosynthesis genes were slightly down-regulated in the pap1-D/fls1ko seedlings as compared to their expression in pap1-D seedlings. We also report the performance of pap1-D/fls1ko seedlings in response to plant osmotic stresses.
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http://dx.doi.org/10.1007/s00299-016-2040-9DOI Listing
November 2016

Chemical Constituents Isolated from the Root Bark of Cudrania tricuspidata and Their Potential Neuroprotective Effects.

J Nat Prod 2016 08 15;79(8):1938-51. Epub 2016 Jul 15.

Natural Products Research Institute, College of Pharmacy, Seoul National University , Seoul 08826, Republic of Korea.

Seventy-five compounds, including 21 new compounds (1-21), were isolated from the root bark of Cudrania tricuspidata. The structures of the isolated compounds were elucidated by interpretation of their spectroscopic data. All isolated compounds were evaluated for their neuroprotective effects against 6-hydroxydopamine (6-OHDA)-induced cell death, and nine compounds had activities with EC50 values of 1.9-30.2 μM. The 75 isolated compounds along with 34 previously reported xanthones were tested also for neuroprotective effects against the 1-methyl-4-phenylpyridinium ion (MPP(+)) and oxygen glucose deprivation (OGD)-induced cell death. Three compounds were active against MPP(+)-induced cell death with EC50 values of 0.2-10.3 μM, and 23 compounds were active in the OGD model with EC50 values of 2.9-35.5 μM.
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http://dx.doi.org/10.1021/acs.jnatprod.6b00204DOI Listing
August 2016

Lanostane Triterpenes Isolated from Antrodia heteromorpha and Their Inhibitory Effects on RANKL-Induced Osteoclastogenesis.

J Nat Prod 2016 06 7;79(6):1689-93. Epub 2016 Jun 7.

Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology , Cheongju 28116, Republic of Korea.

Two new spiro-lanostane triterpenoids, antrolactones A and B (1 and 2), along with polyporenic acid C (3), were isolated from an EtOAc-soluble extract of Antrodia heteromorpha culture medium, and the chemical structures of the new compounds were elucidated by application of NMR, MS, and ECD spectroscopic techniques. All isolated compounds exhibited inhibitory effects on receptor activator of nuclear factor-kappaB ligand-induced osteoclastogenesis.
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http://dx.doi.org/10.1021/acs.jnatprod.6b00207DOI Listing
June 2016

A New Canthinone-Type Alkaloid Isolated from Ailanthus altissima Swingle.

Molecules 2016 May 16;21(5). Epub 2016 May 16.

College of Pharmacy, Kyung Hee University, Seoul 130-701, Korea.

The present investigation of the chemical constituents of the stem barks of Ailanthus altissima has resulted in the isolation of six canthinone-type alkaloids, including a new compound, (R)-5-(1-hydroxyethyl)-canthine-6-one (1), and five known compounds (2-6). Moreover, four phenyl propanoids (7-10), two lignans (11 and 12), two triterpenoids (13 and 14) and a fatty acid (15) having previously known chemical structures were isolated during the same course of this study. The structure of the new compound was elucidated by physical (m.p., [α]D) and spectroscopic data (¹H-NMR, (13)C-NMR, 2D NMR, and HR-DART-MS) interpretation and its absolute configuration was determined by electronic circular dichroism (ECD) data and quantum chemical calculations. The inflammatory activities of the isolates were screened on lipopolysaccharide (LPS)-induced nitric oxide (NO), a proinflammatory mediator, in RAW 264.7 cells. Among these isolated compounds, six compounds exhibited significant inhibition of NO production, with IC50 values in the range of 5.92 ± 0.9 to 15.09 ± 1.8 μM.
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http://dx.doi.org/10.3390/molecules21050642DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273678PMC
May 2016

Characterization of Arabidopsis thaliana FLAVONOL SYNTHASE 1 (FLS1) -overexpression plants in response to abiotic stress.

Plant Physiol Biochem 2016 Jun 9;103:133-42. Epub 2016 Mar 9.

Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-713, Republic of Korea; Institute of Life Science and Natural Resources, Korea University, Seoul 136-713, Republic of Korea. Electronic address:

Flavonoids are an important group of secondary metabolites that are involved in plant growth and contribute to human health. Many studies have focused on the biosynthesis pathway, biochemical characters, and biological functions of flavonoids. In this report, we showed that overexpression of FLS1 (FLS1-OX) not only altered seed coat color (resulting in a light brown color), but also affected flavonoid accumulation. Whereas fls1-3 mutants accumulated higher anthocyanin levels, FLS1-OX seedlings had lower levels than those of the wild-type. Besides, shoot tissues of FLS1-OX plants exhibited lower flavonol levels than those of the wild-type. However, growth performance and abiotic stress tolerance of FLS1-OX, fls1-3, and wild-type plants were not significantly different. Taken together, FLS1 can be manipulated (i.e., silenced or overexpressed) to redirect the flavonoid biosynthetic pathway toward anthocyanin production without negative effects on plant growth and development.
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http://dx.doi.org/10.1016/j.plaphy.2016.03.010DOI Listing
June 2016

Spiroindole Alkaloids and Spiroditerpenoids from Aspergillus duricaulis and Their Potential Neuroprotective Effects.

J Nat Prod 2015 Nov 30;78(11):2572-9. Epub 2015 Oct 30.

Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University , Seoul 02841, Republic of Korea.

Six new spiroindole alkaloids (1-6) and two new spiroditerpenoids (7 and 8) were isolated from an EtOAc extract of Aspergillus duricaulis culture media together with five known compounds. The structures of the isolated compounds were elucidated by analysis of NMR and MS data, and the absolute configurations of compounds 1-8 were confirmed by CD spectroscopic methods. All isolated compounds were evaluated for their inhibition of beta-amyloid (Aβ) aggregate-induced toxicity in PC12 cells and Aβ aggregation. Compounds 8-11 efficiently protected PC12 cells against Aβ aggregate-induced toxicity, but only compound 9 inhibited Aβ aggregation. On the other hand, compounds 4 and 5 exhibited moderate inhibitory effects on Aβ aggregation, but did not protect the cells from Aβ aggregate-induced toxicity. Preincubating Aβ monomers with compounds 4 and 5 rescued PC12 cells against Aβ aggregate-induced toxicity by reducing neurotoxic Aβ aggregates. Compound 9 inhibited both Aβ aggregate-induced toxicity and Aβ aggregation.
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http://dx.doi.org/10.1021/acs.jnatprod.5b00508DOI Listing
November 2015

Chemical constituents isolated from the Mongolian medicinal plant Sophora alopecuroides L. and their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages.

Bioorg Med Chem Lett 2015 Aug 30;25(16):3314-8. Epub 2015 May 30.

Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea. Electronic address:

Three new flavonostilbenes, alopecurones M-O (1-3), were isolated from the root bark of Sophora alopecuroides L. together with 21 known compounds. The structures of the isolated compounds were elucidated by using NMR, MS, and CD spectroscopic data. All isolates were evaluated for their potential to inhibit LPS-induced nitric oxide production in RAW 264.7 cells.
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http://dx.doi.org/10.1016/j.bmcl.2015.05.062DOI Listing
August 2015

Effects of Cudrania tricuspidata Fruit Extract and Its Active Compound, 5,7,3',4'-Tetrahydroxy-6,8-diprenylisoflavone, on the High-Affinity IgE Receptor-Mediated Activation of Syk in Mast Cells.

J Agric Food Chem 2015 Jun 29;63(22):5459-67. Epub 2015 May 29.

†Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea.

Cudrania tricuspidata fruit extract contains a rich source of prenylated flavonoids with potential antiatherosclerotic, hepatoprotective, and anti-inflammatory properties. However, the effect of C. tricuspidata fruit extracts and its active compounds on the high-affinity IgE receptor (FcεRI)-mediated signaling remains unknown. In the present study, the effect of methanol extract from the fruits of C. tricuspidata (MFC) and its active compound, 5,7,3',4'-tetrahydroxy-6,8-diprenylisoflavone (THDPI), on FcεRI-mediated signaling in mast cells was investigated. MFC and THDPI suppressed mast cell degranulation and Ca(2+) influx. MFC also interfered with IgE-FcεRI interaction and decreased FcεRIβ mRNA expression in mast cells. Furthermore, MFC and THDPI inhibited the phosphorylation of Syk, LAT, and PLCγ and F-actin redistribution. These results indicate that MFC and its active compound, THDPI, inhibit mast cell activation through the inhibition of FcεRI-mediated Syk activation, suggesting a therapeutic potential for controlling mast cell activation in inflammatory and/or allergic processes.
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http://dx.doi.org/10.1021/acs.jafc.5b00903DOI Listing
June 2015

Neuroprotection against 6-OHDA-induced oxidative stress and apoptosis in SH-SY5Y cells by 5,7-Dihydroxychromone: Activation of the Nrf2/ARE pathway.

Life Sci 2015 Jun 26;130:25-30. Epub 2015 Mar 26.

Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea. Electronic address:

Aims: The aim of this study was to prove the neuroprotective effect of 5,7-Dihydroxychromone (DHC) through the Nrf2/ARE signaling pathway. To elucidate the mechanism, we investigated whether 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in SH-SY5Y cells could be attenuated by DHC via activating the Nrf2/ARE signal and whether DHC could down-regulate 6-OHDA-induced excessive ROS generation

Main Methods: To evaluate the neuroprotective effect of DHC against 6-OHDA-induced apoptosis, FACS analysis was performed using PI staining. The inhibitory effect of DHC against 6-OHDA-induced ROS generation was evaluated by DCFH-DA staining assay. Additionally, translocation of Nrf2 to the nucleus and increased Nrf2/ARE binding activity, which subsequently resulted in the up-regulation of the Nrf2-dependent antioxidant gene expressions including HO-1, NQO1, and GCLc, were evaluated by Western blotting and EMSA.

Key Findings: Pre-treatment of DHC, one of the constituents of Cudrania tricuspidata, significantly protects 6-OHDA-induced neuronal cell death and ROS generation. Also, DHC inhibited the expression of activated caspase-3 and caspase-9 and cleaved PARP in 6-OHDA-induced SH-SY5Y cells. DHC induced the translocation of Nrf2 to the nucleus and increased Nrf2/ARE binding activity which results in the up-regulation of the expression of Nrf2-dependent antioxidant genes, including HO-1, NQO1, and GCLc. The addition of Nrf2 siRNA abolished the neuroprotective effect of DHC against 6-OHDA-induced neurotoxicity and the expression of Nrf2-mediated antioxidant genes.

Significance: Activation of Nrf2/ARE signal by DHC exerted neuroprotective effects against 6-OHDA-induced oxidative stress and apoptosis. This finding will give an insight that activating Nrf2/ARE signal could be a new potential therapeutic strategy for neurodegenerative disease.
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http://dx.doi.org/10.1016/j.lfs.2015.02.026DOI Listing
June 2015

Isoflavones with neuroprotective activities from fruits of Cudrania tricuspidata.

Phytochemistry 2015 Mar 6;111:141-8. Epub 2014 Dec 6.

Department of Biosystems and Biotechnology, Korea University, Seoul 136-713, Republic of Korea. Electronic address:

Ten isoflavones, cudraisoflavones B-K (1-10), together with 27 known isoflavones, were isolated from the EtOAc soluble extract of fruits of Cudrania tricuspidata. The structures of compounds 1-10 were elucidated on the basis of MS and NMR spectroscopic data, including 2D NMR experiments. Compounds 7-9 and three known (11-13) compounds showed neuroprotective activity against 6-hydroxydopamine induced cell death in human neuroblastoma SH-SY5Y cells, with EC50 values of 0.5-9.2 μM.
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http://dx.doi.org/10.1016/j.phytochem.2014.10.021DOI Listing
March 2015

Neuroprotective Xanthones from the Root Bark of Cudrania tricuspidata.

J Nat Prod 2014 Aug;77(8):1893-901

Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University , Seoul 136-713, Korea.

Seventeen new prenylated xanthones (1-17) were isolated from an ethyl acetate-soluble extract of root bark of Cudrania tricuspidata together with 17 previously identified xanthones. The structures of the new compounds were elucidated by spectroscopic methods. Six new compounds (3, 7, 8, 9, 15, and 16) and six known compounds (18-23) showed neuroprotective effects against 6-hydroxydopamine-induced cell death in human neuroblastoma SH-SY5Y cells, with EC50 values of 0.7-16.6 μM.
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http://dx.doi.org/10.1021/np500364xDOI Listing
August 2014

Metabolomics approach for the discrimination of raw and steamed Gastrodia elata using liquid chromatography quadrupole time-of-flight mass spectrometry.

J Pharm Biomed Anal 2014 Jun 31;94:132-8. Epub 2014 Jan 31.

Department of Biosystems and Biotechnology, Korea University, Seoul 136-713, Republic of Korea. Electronic address:

A liquid chromatography quadrupole time-of-flight mass spectrometry-based metabolomics approach was applied to metabolite profiling of Gastrodia elata in order to identify raw and steamed G. elata and explore potential biomarkers for each processing state. A statistical classification method, significant analysis of microarrays, was used to select influential metabolites from the different forms. Through metabolite selection, several potential biomarkers were determined and assigned by matching mass information with that of reference compounds or by comparing it with data in the literature. Furthermore, the developed method was cross-checked using two validation procedures. The first validation was performed simultaneously with the metabolite profiling of G. elata using all detected metabolites, and the second was performed after the metabolite profiling using representative standard compounds of G. elata. Overall, this study can be applied to quality assurance of G. elata.
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http://dx.doi.org/10.1016/j.jpba.2014.01.032DOI Listing
June 2014