34 results on '"Yoon Joo Ko"'
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2. To which sites were thiols added? Insight into the thiol–yne click-based post-synthetic modification of conjugated microporous polymers
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June Young Jang, Gye Hong Kim, Yoon-Joo Ko, Kyoung Chul Ko, and Seung Uk Son
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Polymers and Plastics ,Organic Chemistry ,Bioengineering ,Biochemistry - Abstract
We suggest that 1,3-diynes are main reaction sites in the thiol–yne click-based main chain post-synthetic modification of conjugated microporous polymers.
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- 2023
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3. Solution structure of the Myb domain of Terfa derived from Zebrafish interacting with both human and plant telomeric DNA
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Weontae Lee, Ji Hye Yun, Yoon Joo Ko, and Min Jung Kim
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0301 basic medicine ,DNA, Plant ,Biophysics ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Protein Domains ,Animals ,MYB ,Molecular Biology ,Zebrafish ,Telomere-binding protein ,Binding Sites ,Base Sequence ,biology ,Cell Biology ,Telomere ,Zebrafish Proteins ,Protein superfamily ,biology.organism_classification ,Cell biology ,DNA-Binding Proteins ,Solutions ,Biomarker ,030104 developmental biology ,chemistry ,030220 oncology & carcinogenesis ,Telomeric DNA binding ,Telomeric-Repeat Binding Factor ,DNA ,Protein Binding - Abstract
Telomeric repeat binding factor a (Terfa) derived from zebrafish is a homologous protein with human telomeric repeat binding factor 2 (TRF2). Terfa is known as a senescence-associated biomarker in various research through the zebrafish animal model. In addition, according to the findings so far, it has been confirmed that human or plant telomere binding proteins bind to telomeric DNA specialized for each species, but, in our result, Terfa shows it strongly binds to both human or plant type telomeric DNA. Here we characterized the DNA binding properties and demonstrate the solution structure of Terfa and identified residues participating in the interaction with both human and plant telomeric DNA. In DNA recognition of human and plant telomere binding proteins, the N-terminal loop and the α-helix 3 part of Myb domain were bound majorly, whereas, in the case of Terfa, the N-terminal loop, the α-helix 1-2 loop, and α-helix 2 of the Myb domain were dominantly bound. Therefore, when Terfa recognizes DNA, it was found that the binding module differs from previously known telomere binding proteins. The comparison of the structure of the telomere binding proteins provides an opportunity to understand more specifically how the structural properties of each telomere binding protein are associated with telomeric DNA binding from an evolutionary point of view.
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- 2021
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4. Discovery and Engineering of a Microbial Double-Oxygenating Lipoxygenase for Synthesis of Dihydroxy Fatty Acids as Specialized Proresolving Mediators
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Jung Ung An, Jin Byung Park, Deok Kun Oh, Jin Lee, Yoon Joo Ko, and Tae-Hun Kim
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biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,General Chemical Engineering ,Inflammation ,02 engineering and technology ,General Chemistry ,Protein engineering ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Lipoxygenase ,Biotransformation ,Biochemistry ,biology.protein ,medicine ,Environmental Chemistry ,medicine.symptom ,0210 nano-technology - Abstract
Specialized proresolving mediators (SPMs), such as resolvins and maresins, resolve inflammation and protect against infection at trace amounts generated by neutrophils and macrophages in humans. Th...
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- 2020
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5. Real-Time In-Organism NMR Metabolomics Reveals Different Roles of AMP-Activated Protein Kinase Catalytic Subunits
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Sang-Min Jeon, Junho Lee, Hanee Lee, Yoon-Joo Ko, Christine H Chung, Yong Jin An, Jin Wook Cha, Sunghyouk Park, and Tin Tin Manh Nguyen
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Time Factors ,biology ,Chemistry ,010401 analytical chemistry ,Master regulator ,AMPK ,Metabolism ,AMP-Activated Protein Kinases ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Biochemistry ,AMP-activated protein kinase ,Catalytic Domain ,biology.protein ,Animals ,Humans ,Metabolomics ,Caenorhabditis elegans ,Protein kinase A ,Nuclear Magnetic Resonance, Biomolecular ,Organism ,Nmr based metabolomics - Abstract
AMP-activated protein kinase (AMPK in human and AAK in C. elegans) is a master regulator of metabolism. It has many isotypes, but its isotype-dependent functions are largely unknown. By developing ...
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- 2020
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6. AB2 polymerization on hollow microporous organic polymers: engineering of solid acid catalysts for the synthesis of soluble cellulose derivatives
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Hae Jin Kim, Kyoungil Cho, Yoon-Joo Ko, Su Kyung Chae, Sang-Moon Lee, and Seung Uk Son
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chemistry.chemical_classification ,Chemical substance ,Polymers and Plastics ,Organic Chemistry ,Sonogashira coupling ,Bioengineering ,Polymer ,Microporous material ,Biochemistry ,Catalysis ,chemistry.chemical_compound ,Monomer ,chemistry ,Polymerization ,Polymer chemistry ,Click chemistry - Abstract
This work shows a new post-synthetic strategy of a microporous organic polymer (MOP) based on AB2 polymerization chemistry (polymerization of AB2-type monomers). Hollow MOP (H-MOP) platforms were prepared by template synthesis via Sonogashira coupling of 1,4-dibromo-2,5-diethynylbenzene. The amount of terminal alkynes in the H-MOP was amplified via AB2 polymerization. Through the thiol–yne click reaction, aliphatic sulfonic acids were incorporated into the terminal alkyne-enriched H-MOP. The resultant solid acid catalysts showed efficient performance in the synthesis of soluble cellulose derivatives.
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- 2020
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7. Additive anti-inflammation by a combination of conjugated linoleic acid and α-lipoic acid through molecular interaction between both compounds
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Chong-Su Cho, Yun-Jaie Choi, Ki-June Lee, Sang-Kee Kang, Yoon-Joo Ko, and Whee-Soo Kim
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integumentary system ,Lipopolysaccharide ,Alpha-Lipoic Acid ,Conjugated linoleic acid ,food and beverages ,Peroxisome ,Applied Microbiology and Biotechnology ,Article ,In vitro ,Lipoic acid ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Extracellular ,lipids (amino acids, peptides, and proteins) ,Receptor ,Food Science ,Biotechnology - Abstract
Alpha lipoic acid (LA) and conjugated linoleic acid (CLA) have been well-documented on a variety of functional effects in health foods. The main purpose of this study was focused on the additive anti-inflammatory activity of the combination of LA and CLA in vitro. Raw 264.7 cells induced by lipopolysaccharide were treated with LA and CLA individually or in combination at a variety of concentration ranges. Co-treating 25 μM of LA and 25 μM of CLA significantly inhibited pro-inflammatory cytokines compared to the same concentration of single LA- or CLA-treated group. The molecular mechanism of anti-inflammation by a combination of these compounds was attributed to extracellular signal-regulated kinase-1 (ERK1) and peroxisome proliferator-activated receptor gamma (PPARγ). Also, the molecular interaction between both compounds was confirmed by NMR. Our findings suggested that the combination of CLA and LA showed potential additive effect on anti-inflammation through the molecular interaction of both compounds. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10068-019-00677-7) contains supplementary material, which is available to authorized users.
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- 2019
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8. Colloidal Template Synthesis of Nanomaterials by Using Microporous Organic Nanoparticles: The Case of C@MoS 2 Nanoadsorbents
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Shin Young Kang, Yoon-Joo Ko, Hae Jin Kim, Dong Wook Kim, Jae-Won Choi, Seung Uk Son, Sang-Moon Lee, Chang Wan Kang, and Yoon Myung
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010405 organic chemistry ,Chemistry ,Organic Chemistry ,Cationic polymerization ,Nanoparticle ,General Chemistry ,Microporous material ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Nanomaterials ,Colloid ,chemistry.chemical_compound ,Adsorption ,Chemical engineering ,Zeta potential ,Methylene blue - Abstract
The so-called colloidal template synthesis has been applied to the preparation of surface-engineered nanoadsorbents. Colloidal microporous organic network nanotemplates (C-MONs), which showed a high surface area (611 m2 g-1 ) and enhanced microporosity, were prepared through the networking of organic building blocks in the presence of poly(vinylpyrrolidone) (PVP). Owing to entrapment of the PVP in networks, the C-MONs showed good colloidal dispersion in EtOH. MoS2 precursors were incorporated into the C-MONs and heat treatment afforded core-shell-type C@MoS2 nanoparticles with a diameter of 80 nm, a negative zeta potential (-39.5 mV), a high surface area (508 m2 g-1 ), and excellent adsorption performance towards cationic dyes (qmax =343.6 and 421.9 mg g-1 for methylene blue and rhodamine B, respectively).
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- 2019
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9. Sesquiterpenes from Curcuma zedoaria rhizomes and their cytotoxicity against human gastric cancer AGS cells
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Yoon-Joo Ko, Sang J. Chung, Seoung Rak Lee, Tae Kyoung Lee, Ki-Hyun Kim, Dahae Lee, and Ki Sung Kang
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Models, Molecular ,Cell Survival ,01 natural sciences ,Biochemistry ,High-performance liquid chromatography ,Structure-Activity Relationship ,Curcuma ,food ,Drug Discovery ,Tumor Cells, Cultured ,medicine ,Humans ,Cytotoxic T cell ,Viability assay ,Cytotoxicity ,Molecular Biology ,Density Functional Theory ,Cell Proliferation ,Dose-Response Relationship, Drug ,Molecular Structure ,Traditional medicine ,biology ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Cancer ,biology.organism_classification ,medicine.disease ,Antineoplastic Agents, Phytogenic ,food.food ,0104 chemical sciences ,Rhizome ,010404 medicinal & biomolecular chemistry ,Zingiberaceae ,Drug Screening Assays, Antitumor ,Curcuma zedoaria ,Sesquiterpenes - Abstract
Curcuma zedoaria rhizome (Zingiberaceae) is a well-known traditional medicinal plant used in Ayurvedic and traditional Chinese medicine to treat various cancers. This study aimed to identify the cytotoxic components from C. zedoaria rhizomes that act against gastric cancer, which is the third leading cause of death from cancer worldwide because the MeOH extract of C. zedoaria rhizome was found to show a cytotoxic effect against gastric cancer AGS cells. Repeated column chromatography and semi-preparative HPLC purification were used to separate the components from the C. zedoaria MeOH extract. Two new sesquiterpenes, curcumenol-9,10-epoxide (1) and curcuzedoalide B (2), and 12 known related sesquiterpenes (3–14) were isolated from the C. zedoaria MeOH extract. The structures of new compounds were determined by 1D and 2D NMR spectroscopic experiments and HR-ESIMS, and quantum chemical ECD calculations. The cytotoxic effects of the isolated compounds were measured in human gastric cancer AGS cells using an MTT cell viability assay. Compounds 9, 10, and 12 exhibited cytotoxic effects against gastric cancer AGS cells, with IC50 values in the range of 212–392 μM. These findings provide further experimental scientific evidence to support the traditional use of C. zedoaria rhizomes for the treatment of cancer. Curcumenol (9), 4,8-dioxo-6β-methoxy-7α,11-epoxycarabrane (10), and zedoarofuran (12) were identified as the main cytotoxic components in C. zedoaria rhizomes.
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- 2019
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10. Room-Temperature Synthesis of a Hollow Microporous Organic Polymer Bearing Activated Alkyne IR Probes for Nonradical Thiol-yne Click-Based Post-Functionalization
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Sang Moon Lee, Seung Uk Son, Hae Jin Kim, Yoon-Joo Ko, Jong In Park, Kyoung Chul Ko, Hye-Young Jang, and June Young Jang
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chemistry.chemical_classification ,Organic polymer ,010405 organic chemistry ,Organic Chemistry ,Alkyne ,General Chemistry ,Microporous material ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Ion ,Adsorption ,chemistry ,Polymer chemistry ,Click chemistry ,Thiol ,Surface modification - Abstract
This work shows that hollow microporous organic polymer (H-MOP-A) with activated internal alkynes as IR probes can be prepared by template synthesis based on acyl Sonogashira-Hagihara coupling at room temperature. The H-MOP-A is a versatile platform in the main chain PSM based on nonradical thiol-yne click reaction. Moreover, an IR peak of internal alkynes in the H-MOP-A is very intense and could be utilized in the monitoring of thiol-yne click-based main chain PSM. The functionalized H-MOP-A with carboxylic acids (H-MOP-CA) showed efficient adsorption toward Ag + ions. The resultant H-MOP-CA-Ag showed excellent performance in the CO 2 fixation to α-alkylidene cyclic compounds.
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- 2021
11. Ginkwanghols A and B, osteogenic coumaric acid-aliphatic alcohol hybrids from the leaves of Ginkgo biloba
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Kwang Ho Lee, Se Yun Jeong, Jung Kyu Kim, Seon-Hee Kim, Jin-Chul Kim, Jae Sik Yu, Yoon-Joo Ko, Jin Hee Choi, and Ki Hyun Kim
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0301 basic medicine ,Coumaric Acids ,Alcohol ,Coumaric acid ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Osteogenesis ,Drug Discovery ,Animals ,Osteopontin ,Cells, Cultured ,biology ,Molecular Structure ,Ginkgo biloba ,Ginkgo ,Organic Chemistry ,Biological activity ,Cell Differentiation ,biology.organism_classification ,Ginkgoaceae ,Plant Leaves ,030104 developmental biology ,chemistry ,Biochemistry ,030220 oncology & carcinogenesis ,Alcohols ,biology.protein ,Molecular Medicine ,Alkaline phosphatase - Abstract
Ginkgo biloba (Ginkgoaceae), commonly known as "ginkgo", is called a living fossil, and it has been cultivated early in human history for various uses in traditional medicine and as a source of food. As part of ongoing research to explore the chemical diversity and biologically active compounds from natural resources, two new coumaric acid-aliphatic alcohol hybrids, ginkwanghols A (1) and B (2) were isolated from the leaves of G. biloba. The coumaric acid-aliphatic alcohol hybrids of natural products have rarely been reported. The structures of the new compounds were determined by extensive NMR spectroscopic analysis, HRESI-MS, and quantum chemical ECD calculations, and by comparing the experimental HRESI-MS/MS spectrum of chemically transformed compound 1a with the predicted HRESI-MS/MS spectra proposed from CFM-ID 3.0, a software tool for MS/MS spectral prediction and MS-based compound identification. Ginkwanghols A (1) and B (2) increased alkaline phosphatase (ALP) production in C3H10T1/2, a mouse mesenchymal stem cell line, in a dose-dependent manner. In addition, ginkwanghols A and B mediated the promotion of osteogenic differentiation as indicated by the induction of the mRNA expression of the osteogenic markers ALP and osteopontin (OPN).
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- 2021
12. NMR spectroscopy uncovers direct interaction between BAF60A and p53
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Kyoung-Seok Ryu, Wonbin Lee, Weontae Lee, Ji Hye Yun, Sunjin Moon, Taehee Kim, Yoon Joo Ko, Jeongmin Han, and Jae Hyun Park
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0301 basic medicine ,Subfamily ,Chromosomal Proteins, Non-Histone ,Biophysics ,Regulator ,Biochemistry ,Weak binding ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Nucleosome ,Humans ,Protein Interaction Domains and Motifs ,Protein Interaction Maps ,Molecular Biology ,Nuclear Magnetic Resonance, Biomolecular ,Binding Sites ,Chemistry ,Cell Biology ,Nuclear magnetic resonance spectroscopy ,Chromatin ,Dissociation constant ,Molecular Docking Simulation ,030104 developmental biology ,030220 oncology & carcinogenesis ,Tumor Suppressor Protein p53 ,DNA - Abstract
The BRG1-associated factor 60A (BAF60A), an SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily D member 1, has been known to be important for transcriptional activation and inhibition through the alteration of the DNA nucleosome. Although the association between BAF60A and p53 plays a critical role in tumor suppression, the interaction mode is still unclear. Here, we report the detailed interactions between BAF60A and p53 by both NMR spectroscopy and pull-down analysis. Both N-terminal region (BAF60ANR) and the SWIB domain (BAF60ASWIB) of BAF60A directly interact with the tetramerization domain of p53 (p53TET). NMR data show that Ile315, Met366, Ala388, and Tyr390 of BAF60ASWIB are mostly involved in p53TET binding. The calculated dissociation constant (KD) value between BAF60ASWIB and p53TET revealed relatively weak binding affinity, at approximately 0.3 ± 0.065 mM. Our data will enhance detailed interaction mechanism to elucidate the molecular basis of p53-mediated integration via BAF60A interaction.
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- 2020
13. Ginkgobilol, a new diarylpentanoid and an osteogenic diarylpentanoid analog from Ginkgo biloba leaves
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Ki Hyun Kim, Kwang Ho Lee, Seon-Hee Kim, Jae Sik Yu, Yoon-Joo Ko, Jin Hee Choi, and Changhyun Pang
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Clinical Biochemistry ,Phytochemicals ,Pharmaceutical Science ,01 natural sciences ,Biochemistry ,Cell Line ,chemistry.chemical_compound ,Mice ,Osteogenesis ,Drug Discovery ,Gene expression ,Animals ,Osteopontin ,Molecular Biology ,biology ,010405 organic chemistry ,Ginkgo biloba ,Plant Extracts ,Organic Chemistry ,Mesenchymal stem cell ,Absolute configuration ,Cell Differentiation ,Mesenchymal Stem Cells ,biology.organism_classification ,Alkaline Phosphatase ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry ,Phytochemical ,Active compound ,biology.protein ,Molecular Medicine ,Specific rotation - Abstract
Phytochemical analysis of methanol extracts of Ginkgo biloba leaves resulted in the isolation of a novel diarylpentanoid, ginkgobilol (1) and a known diarylpentanoid analog (2). The structure of the new compound was elucidated by analyzing NMR spectroscopic data and HR-ESIMS, and the absolute configuration was determined using gauge-including atomic orbital NMR chemical shift calculations, followed by DP4+ analysis and specific rotation value. Diarylpentanoids comprise two aromatic rings linked by a five-carbon bridge; these are relatively unique examples in natural products. To the best of our knowledge, the present study is the first to report the presence of diarylpentanoids in G. biloba. Compound 2 increased alkaline phosphatase (ALP) production in C3H10T1/2, a murine mesenchymal stem cell line, in a dose-dependent manner. The promotion of osteogenic differentiation by the active compound 2 mediated by induction of transcriptional ALP and osteopontin (OPN) gene expression was confirmed using quantitative real time polymerase chain reaction, thus indicating its remarkable bone formation activity.
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- 2020
14. Microbial Synthesis of Linoleate 9S-Lipoxygenase Derived Plant C18 Oxylipins from C18 Polyunsaturated Fatty Acids
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Jung-Ung An, Deok-Kun Oh, Yoon-Joo Ko, and In Gyu Lee
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0106 biological sciences ,Myxococcus xanthus ,Lipoxygenase ,01 natural sciences ,chemistry.chemical_compound ,Bacterial Proteins ,Biotransformation ,Biosynthesis ,Tandem Mass Spectrometry ,Oxylipins ,Epoxide hydrolase ,chemistry.chemical_classification ,Molecular Structure ,biology ,Chemistry ,fungi ,010401 analytical chemistry ,food and beverages ,General Chemistry ,biology.organism_classification ,0104 chemical sciences ,Enzyme ,Biochemistry ,Microsomal epoxide hydrolase ,Biocatalysis ,Fatty Acids, Unsaturated ,biology.protein ,General Agricultural and Biological Sciences ,Bacteria ,010606 plant biology & botany ,Polyunsaturated fatty acid - Abstract
Plant oxylipins, including hydroxy fatty acids, epoxy hydroxy fatty acids, and trihydroxy fatty acids, which are biosynthesized from C18 polyunsaturated fatty acids (PUFAs), are involved in pathogen-specific defense mechanisms against fungal infections. However, their quantitative biotransformation by plant enzymes has not been reported. A few bacteria produce C18 trihydroxy fatty acids, but the enzymes and pathways related to the biosynthesis of plant oxylipins in bacteria have not been reported. In this study, we first report the biotransformation of C18 PUFAs into plant C18 oxylipins by expressing linoleate 9 S-lipoxygenase with and without epoxide hydrolase from the proteobacterium Myxococcus xanthus in recombinant Escherichia coli. Among the nine types of plant oxylipins, 12,13-epoxy-14-hydroxy- cis, cis-9,15-octadecadienoic acid was identified as a new compound by NMR analysis, and 9,10,11-hydroxy- cis, cis-6,12-octadecadienoic acid and 12,13,14-trihydroxy- cis, cis-9,15-octadecadienoic were suggested as new compounds by LC-MS/MS analysis. This study shows that bioactive plant oxylipins can be produced by microbial enzymes.
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- 2019
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15. Microporous organic polymer-induced gel electrolytes for enhanced operation stability of electrochromic devices
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Jae-Won Choi, Hae Jin Kim, June Young Jang, Yoon-Joo Ko, Ju Hong Ko, Sang-Moon Lee, Seung Uk Son, and Hyunjae Lee
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chemistry.chemical_classification ,Organic polymer ,Materials science ,Polymers and Plastics ,Organic Chemistry ,technology, industry, and agriculture ,Bioengineering ,02 engineering and technology ,Polymer ,Electrolyte ,Microporous material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochromic devices ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,chemistry ,Chemical engineering ,parasitic diseases ,Molecule ,0210 nano-technology - Abstract
Gel electrolytes were synthesized by the formation of microporous organic polymers in the presence of 0.077–0.77 M LiClO4 and N-methylpyrrolidone. Electrochromic devices fabricated using the gel electrolytes showed enhanced operation stability, compared with those fabricated using liquid electrolytes, which is attributable to the efficient separation of working viologens from counting molecules.
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- 2019
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16. Enzymatic synthesis of new hepoxilins and trioxilins from polyunsaturated fatty acids
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Jung Ung An, Yoon Joo Ko, Deok Kun Oh, In Gyu Lee, and Jin Byung Park
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chemistry.chemical_classification ,010405 organic chemistry ,Lipid signaling ,Enzymatic synthesis ,010402 general chemistry ,01 natural sciences ,Pollution ,Environmentally friendly ,0104 chemical sciences ,Enzyme ,Biotransformation ,chemistry ,Biochemistry ,Microbial enzymes ,Environmental Chemistry ,Epoxide hydrolase ,Polyunsaturated fatty acid - Abstract
Hepoxilins (HXs) and trioxilins (TrXs) are lipid mediators that regulate diverse physiological processes at trace amounts in humans. They have been synthesized by chemical methods, which have disadvantages such as low yield, byproduct formation, and use of toxic chemical reagents. Here, we reported the identification of ten types of HXs and TrXs synthesized by recombinant Escherichia coli expressing bacterial arachidonate 15-lipoxygenase and/or epoxide hydrolase using five polyunsaturated fatty acids (PUFAs). Of these, eight types were new. The discovery was due to the microbial enzymes with high activities for the same catalytic activities as those of human enzymes. We succeeded in the efficient, cost-effective, and environmentally friendly biotransformation of PUFAs into nine types of HXs and TrXs by cells, yielding >10 g L−1 of 14,15-HXB3 and 13,14,15-TrXB3, with conversion yields of >70%. Our study contributes to the environmentally friendly synthesis of medicinally important lipid mediators.
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- 2019
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17. 7α,15-Dihydroxydehydroabietic acid from Pinus koraiensis inhibits the promotion of angiogenesis through downregulation of VEGF, p-Akt and p-ERK in HUVECs
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Jae Sik Yu, Seong Taek Oh, Yoon-Joo Ko, Changhyun Pang, Jun Yeon Park, Tae Kyoung Lee, Ki-Hyun Kim, Tae Su Jang, and Ki Sung Kang
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Vascular Endothelial Growth Factor A ,0301 basic medicine ,Angiogenesis ,medicine.medical_treatment ,Clinical Biochemistry ,Down-Regulation ,Pharmaceutical Science ,Pharmacology ,01 natural sciences ,Biochemistry ,Umbilical vein ,Structure-Activity Relationship ,03 medical and health sciences ,chemistry.chemical_compound ,Downregulation and upregulation ,Drug Discovery ,Human Umbilical Vein Endothelial Cells ,medicine ,Humans ,Extracellular Signal-Regulated MAP Kinases ,Molecular Biology ,Dose-Response Relationship, Drug ,Molecular Structure ,Neovascularization, Pathologic ,Pinus koraiensis ,010405 organic chemistry ,Organic Chemistry ,Biological activity ,Phenolic acid ,Pinus ,0104 chemical sciences ,030104 developmental biology ,chemistry ,Abietanes ,Molecular Medicine ,Signal transduction ,Proto-Oncogene Proteins c-akt ,Adjuvant - Abstract
Pinus koraiensis pinecones are considered an undesired waste by-product of the processing of seeds. However, recent studies of the potential anti-tumor effects of the pinecones have led to increasing interest in their chemical constituents. The present study examined the potential antiangiogenic effects of the constituents of pinecones and further characterized their underlying mechanisms of action. Chemical investigation of a water extract of P. koraiensis pinecones led to the isolation and identification of the eight main components including five diterpenoids (1-5), two monoterpenes (6,7) and a phenolic acid (8). The structure of the compounds was determined by spectroscopic analysis of NMR spectra and LC/MS analysis. Of the isolated compounds, 7α,15-dihydroxydehydroabietic acid (5) significantly inhibited the promotion of angiogenesis in human umbilical vein endothelial cells (HUVECs). Compound 5 inhibited angiogenesis through downregulation of the VEGF, p-Akt and p-ERK signaling pathways. These results provide experimental evidence of a novel biological activity of 7α,15-dihydroxydehydroabietic acid (5) as a potential antiangiogenic substance. This study also suggests that compound 5 could potentially be a useful adjuvant therapeutic substance for cancer prevention and treatment.
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- 2018
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18. Bioactivity-guided isolation and chemical characterization of antiproliferative constituents from morel mushroom (Morchella esculenta) in human lung adenocarcinoma cells
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Yoon-Joo Ko, Tae Su Jang, Seul Lee, Kwan-Hyuck Baek, Hyun Bong Park, Seoung Rak Lee, Hyun-Soo Roh, and Ki Hyun Kim
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0301 basic medicine ,Cytotoxicity ,Medicine (miscellaneous) ,Apoptosis ,Morchella esculenta ,03 medical and health sciences ,0302 clinical medicine ,In vivo ,medicine ,TX341-641 ,Cancer ,Mushroom ,Nutrition and Dietetics ,biology ,Chemistry ,Nutrition. Foods and food supply ,food and beverages ,medicine.disease ,biology.organism_classification ,In vitro ,030104 developmental biology ,Biochemistry ,Cell culture ,030220 oncology & carcinogenesis ,Adenocarcinoma ,Chemical characterization ,Food Science - Abstract
Morchella esculenta (Morchellaceae), one of the most widely appreciated wild edible mushrooms, has demonstrated antitumor activity both in vivo and in vitro. However, the molecular basis underlying its antitumor activity has not yet been elucidated. In this study, we examined the biological effects of the MeOH extract of M. esculenta fruiting bodies on four human lung adenocarcinoma cell lines. Bioactivity-guided fractionation of the MeOH extract followed by chemical investigation of its most cytotoxic hexane-soluble fraction led to the isolation of eight compounds (1 −8), including three fatty acids and five sterols. This is the first report of the isolation of compounds 1 and 3–7 from M. esculenta. Among the eight isolated compounds tested, compounds 1, 3, and 5 exhibited the most potent cytotoxicity to human lung cancer cell lines, with IC50 values ranging from 156.9 to 278 M; this activity was mediated by induction of apoptosis.
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- 2018
19. The effects of phenolic glycosides from Betula platyphylla var. japonica on adipocyte differentiation and mature adipocyte metabolism
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Eun-Bi Ma, Joo Young Huh, Ki Hyun Kim, Jiwon Baek, Seulah Lee, Hee Jeong Eom, and Yoon-Joo Ko
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0301 basic medicine ,Cell Survival ,Short Communication ,mature adipocyte metabolism ,Japonica ,Mice ,Structure-Activity Relationship ,03 medical and health sciences ,chemistry.chemical_compound ,Phenols ,phenolic glycoside ,3T3-L1 Cells ,Adipocyte ,Drug Discovery ,Adipocytes ,Animals ,Lipolysis ,Glycosides ,adipocyte differentiation ,Betula ,Cells, Cultured ,Pharmacology ,chemistry.chemical_classification ,Dose-Response Relationship, Drug ,Molecular Structure ,biology ,Adiponectin ,lcsh:RM1-950 ,Glycoside ,Cell Differentiation ,Catechin ,General Medicine ,biology.organism_classification ,catechin glycoside ,lcsh:Therapeutics. Pharmacology ,030104 developmental biology ,chemistry ,Biochemistry ,Adipogenesis ,Betula platyphylla var. japonica ,Betula platyphylla - Abstract
Betula platyphylla var. japonica (Betulaceae) has been used traditionally in Asian countries for the treatment of inflammatory diseases. A recent study has reported a phenolic compound, platyphylloside from B. platyphylla, that shows inhibition on adipocyte differentiation and induces lipolysis in 3T3-L1 cells. Based on this finding, we conducted phytochemical analysis of the EtOH extract of the bark of B. platyphylla var. japonica, which resulted in the isolation of phenolic glycosides (1–4). Treatment of the isolated compounds (1–4) during adipocyte differentiation of 3T3-L1 mouse adipocytes resulted in dose-dependent inhibition of adipogenesis. In mature adipocytes, arylbutanoid glycosides (2–4) induced lipolysis related genes HSL and ATGL, whereas catechin glycoside (1) had no effect. Additionally, arylbutanoid glycosides (2–4) also induced GLUT4 and adiponectin mRNA expression, indicating improvement in insulin signaling. This suggests that the isolates from B. platyphylla var. japonica exert benefial effects in regulation of adipocyte differentiation as well as adipocyte metabolism., Graphical Abstract
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- 2018
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20. Biotransformation of polyunsaturated fatty acids to bioactive hepoxilins and trioxilins by microbial enzymes
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Do-Young Yoon, Yoon-Joo Ko, Deok-Kun Oh, Jung-Ung An, Yong-Seok Song, and Kyoung-Rok Kim
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0301 basic medicine ,Myxococcus xanthus ,Science ,General Physics and Astronomy ,Arachidonate 12-Lipoxygenase ,Arachidonate Lipoxygenases ,General Biochemistry, Genetics and Molecular Biology ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,8,11,14-Eicosatrienoic Acid ,Biotransformation ,Bacterial Proteins ,Epoxide hydrolase ,lcsh:Science ,chemistry.chemical_classification ,Epoxide Hydrolases ,Multidisciplinary ,biology ,Molecular Structure ,Chemistry ,General Chemistry ,Peroxisome ,biology.organism_classification ,Eicosapentaenoic acid ,030104 developmental biology ,Biochemistry ,Docosahexaenoic acid ,Fatty Acids, Unsaturated ,Arachidonic acid ,lcsh:Q ,030217 neurology & neurosurgery ,Metabolic Networks and Pathways ,Polyunsaturated fatty acid - Abstract
Hepoxilins (HXs) and trioxilins (TrXs) are involved in physiological processes such as inflammation, insulin secretion and pain perception in human. They are metabolites of polyunsaturated fatty acids (PUFAs), including arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid, formed by 12-lipoxygenase (LOX) and epoxide hydrolase (EH) expressed by mammalian cells. Here, we identify ten types of HXs and TrXs, produced by the prokaryote Myxococcus xanthus, of which six types are new, namely, HXB5, HXD3, HXE3, TrXB5, TrXD3 and TrXE3. We succeed in the biotransformation of PUFAs into eight types of HXs (>35% conversion) and TrXs (>10% conversion) by expressing M. xanthus 12-LOX or 11-LOX with or without EH in Escherichia coli. We determine 11-hydroxy-eicosatetraenoic acid, HXB3, HXB4, HXD3, TrXB3 and TrXD3 as potential peroxisome proliferator-activated receptor-γ partial agonists. These findings may facilitate physiological studies and drug development based on lipid mediators., Hepoxilins (HXs) and trioxilins (TrXs) are lipid metabolites with roles in inflammation and insulin secretion. Here, the authors discover a prokaryotic source of HXs and TrXs, identify the biosynthetic enzymes and heterologously express HXs and TrXs in E. coli.
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- 2018
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21. Ginkgonitroside, a new nitrophenyl glycoside and bioactive compounds from Ginkgo biloba leaves controlling adipocyte and osteoblast differentiation
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Kwang Ho Lee, Jung Kyu Kim, Kun Hee Park, Se Yun Jeong, Ki-Hyun Kim, Jin-Chul Kim, Seon-Hee Kim, and Yoon-Joo Ko
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Clinical Biochemistry ,Pharmaceutical Science ,Biochemistry ,Cell Line ,Mice ,chemistry.chemical_compound ,Adipocyte ,Drug Discovery ,Adipocytes ,medicine ,Animals ,Glycosides ,Molecular Biology ,chemistry.chemical_classification ,Osteoblasts ,biology ,Chemistry ,Ginkgo biloba ,Organic Chemistry ,Mesenchymal stem cell ,Glycoside ,Cell Differentiation ,Mesenchymal Stem Cells ,Osteoblast ,biology.organism_classification ,Plant Leaves ,medicine.anatomical_structure ,Molecular Medicine ,Two-dimensional nuclear magnetic resonance spectroscopy - Abstract
Eight compounds (1-8) including one novel nitrophenyl glycoside, ginkgonitroside (1) were isolated from the leaves of Ginkgo biloba, a popular medicinal plant. The structure of the new compound was characterized using extensive spectroscopic analyses via 1D and 2D NMR data interpretations, HR-ESIMS, and chemical transformation. To the best of our knowledge, the present study is the first to report the presence of nitrophenyl glycosides, which are relatively unique phytochemicals in natural products, in G. biloba. The isolated compounds (1-8) were examined for their effects on the regulation of mesenchymal stem cell (MSC) differentiation. Compounds 1-3 and 8 were able to suppress MSC differentiation toward adipocytes. In contrast, compounds 5 and 8 showed activity promoting osteogenic differentiation of MSCs. These findings demonstrate that the active compounds showed regulatory activity on MSC differentiation between adipocytes and osteocytes.
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- 2021
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22. C-terminal tail of NADPH oxidase organizer 1 (Noxo1) mediates interaction with NADPH oxidase activator (Noxa1) in the NOX1 complex
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Yun Soo Bae, Myeongkyu Kim, Weontae Lee, Ji Hye Yun, Yoon Joo Ko, and Pravesh Shrestha
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Models, Molecular ,0301 basic medicine ,HNCA experiment ,Proline ,Biophysics ,Biochemistry ,SH3 domain ,src Homology Domains ,03 medical and health sciences ,0302 clinical medicine ,Humans ,Amino Acid Sequence ,Molecular Biology ,NADPH oxidase organizer 1 ,Adaptor Proteins, Signal Transducing ,NADPH oxidase ,biology ,Activator (genetics) ,Cell Biology ,Adaptor Proteins, Vesicular Transport ,Cytosol ,030104 developmental biology ,NOX1 ,biology.protein ,Sequence Alignment ,030217 neurology & neurosurgery ,Heteronuclear single quantum coherence spectroscopy ,Protein Binding - Abstract
NOX1 (NADPH oxidase) similar to phagocyte NADPH oxidase, is expressed mainly in the colon epithelium and it is responsible for host defense against microbial infections by generating ROS (reactive oxygen species). NOX1 is activated by two regulatory cytosolic proteins that form a hetero-dimer, Noxo1 (NOX organizer 1) and Noxa1 (NOX activator 1). The interaction between Noxa1 and Noxo1 is critical for activating NOX1. However no structural studies for interaction between Noxa1 and Noxo1 has not been reported till date. Here, we studied the inter-molecular interaction between the SH3 domain of Noxa1 and Noxo1 using pull-down assay and NMR spectroscopy. 15N/13C-labeled SH3 domain of Noxa1 has been purified for hetero-nuclear NMR experiments (HNCACB, CBCACONH, HNCA, HNCO, and HSQC). TALOS analysis using backbone assignment data of the Noxa1 SH3 domain showed that the structure primarily consists of β-sheets. Data from pull-down assay between the Noxo1 and Noxa1 showed that the SH3 domains (Noxa1) is responsible for interaction with Noxo1 C-terminal tail harboring proline rich region (PRR). The concentration-dependent titration of the Noxo1 C-terminal tail to Noxa1 shows that Noxo1 particularly in the RT loop: Q407*, H408, S409, A412*, G414*, E416, D417, L418, and F420; n-Src loop: C430, E431*, V432*, A435, W436, and L437; and terminal region: I447; F448*, F452* and V454 interact with Noxa1. Our results will provide a detailed understanding for interaction between Noxa1 and Noxo1 at the molecular level, providing insights into their cytoplasmic activity-mediated functioning as well as regulatory role of C-terminal tail of Noxo1 in the NOX1 complex.
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- 2017
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23. NMR uncovers direct interaction between human NEDD4-1 and p34SEI−1
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Pravesh Shrestha, Dong Hoon Jin, Ki Yup Nam, Kyu Jeong Yeon, Hye Dong Yoo, Dooseop Kim, Heejong Lee, Weontae Lee, Ji Hye Yun, and Yoon Joo Ko
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0301 basic medicine ,biology ,Akt/PKB signaling pathway ,Biophysics ,Regulator ,NEDD4 ,macromolecular substances ,Cell Biology ,Biochemistry ,Molecular biology ,Ubiquitin ligase ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,Ubiquitin ,biology.protein ,PTEN ,Binding site ,Molecular Biology ,PI3K/AKT/mTOR pathway - Abstract
PTEN, an important tumor suppressor and a key regulator of the PI3K/AKT signaling pathway, is often deleted/mutated in different types of cancer. The E3 ubiquitin ligase NEDD4-1 catalyzes the polyubiquitination of PTEN, thereby acting as a negative regulator of PTEN. Stability of NEDD4-1, in turn, is tightly controlled by a 34 kDa oncoprotein, p34 SEI−1 and it regulates PTEN degradation and activates PI3K/AKT pathway, resulting in cancer metastasis. p34 SEI−1 affects not only the expression of NEDD4-1 during transcription and translation but also the subcellular localization of PTEN. This emphasizes the need to understand, at molecular level, the interaction between NEDD4-1 and p34 SEI−1 . A recent study showed that NEDD4-1 interacts with p34 SEI−1 via its WWI domain. However, a detailed interaction for molecular level is yet unknown. We report that the WW1 domain of NEDD4-1 recognizes the SERTA domain containing the proline rich region (PRR motif) in p34 SEI−1 . TALOS analysis based on NMR data confirms three conserved β-sheets in NEDD4-1 WW1 and the central β-sheet of NEDD4-1 WW1 plays a role for protein stability by the backbone dynamics experiments. NMR titration data revealed the binding site for p34 SEI−1 with NEDD4-1. Our data will provide insights into the molecular mechanism of NEDD4-1 and p34 SEI−1 interaction, which will be directly used for drug design which inhibits the molecular interaction involved in different cancer signaling.
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- 2017
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24. Carbon Isotopomer Analysis with Non-Unifom Sampling HSQC NMR for Cell Extract and Live Cell Metabolomics Studies
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Yoon-Joo Ko, Sven G. Hyberts, Yong Jin An, Jin Wook Cha, He Wen, Sunghyouk Park, and Sujin Lee
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0301 basic medicine ,Resolution (mass spectrometry) ,Cell Survival ,Cell ,Acetates ,Specimen Handling ,Analytical Chemistry ,Isotopomers ,Mice ,03 medical and health sciences ,Metabolomics ,Cell Line, Tumor ,medicine ,Animals ,Carbon-13 Magnetic Resonance Spectroscopy ,Carbon Isotopes ,Leukemia ,Chromatography ,Chemistry ,Sampling (statistics) ,Carbon-13 NMR ,030104 developmental biology ,medicine.anatomical_structure ,Biochemistry ,Acetylation ,Metabolic Networks and Pathways ,Heteronuclear single quantum coherence spectroscopy - Abstract
Isotopomer analysis using either 13C NMR or LC/GC–MS has been an invaluable tool for studying metabolic activities in a variety of systems. Traditional challenges are, however, that 13C-detected NMR is insensitive despite its high resolution, and that MS-based techniques cannot easily differentiate positional isotopomers. In addition, current 13C NMR or LC/GC–MS has limitations in detecting metabolites in living cells. Here, we describe a non-uniform sampling-based 2D heteronuclear single quantum coherence (NUS HSQC) approach to measure metabolic isotopomers in both cell lysates and living cells. The method provides a high resolution that can resolve multiplet structures in the 13C dimension while retaining the sensitivity of the 1H-indirect detection. The approach was tested in L1210 mouse leukemia cells labeled with 13C acetate by measuring NUS HSQC with 25% sampling density. The results gave a variety of metabolic information such as (1) higher usage of acetate in acetylation pathway than aspartate syn...
- Published
- 2016
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25. Application of a Smartphone Metabolomics Platform to the Authentication ofSchisandra sinensis
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Sunghyouk Park, Yoon-Joo Ko, Hong-Duc Phan, Hyuk Nam Kwon, and Wen Jun Xu
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0301 basic medicine ,Authentication ,business.industry ,Chemistry ,010401 analytical chemistry ,Plant Science ,General Medicine ,Machine learning ,computer.software_genre ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Analytical Chemistry ,03 medical and health sciences ,030104 developmental biology ,Metabolomics ,Complementary and alternative medicine ,Drug Discovery ,Molecular Medicine ,Herbal preparations ,Artificial intelligence ,business ,computer ,Food Science - Abstract
Introduction Herbal medicines have been used for a long time all around the world. Since the quality of herbal preparations depends on the source of herbal materials, there has been a strong need to develop methods to correctly identify the origin of materials. Objective To develop a smartphone metabolomics platform as a simpler and low-cost alternative for the identification of herbal material source. Methodology Schisandra sinensis extracts from Korea and China were prepared. The visible spectra of all samples were measured by a smartphone spectrometer platform. This platform included all the necessary measures built-in for the metabolomics research: data acquisition, processing, chemometric analysis and visualisation of the results. The result of the smartphone metabolomics platform was compared to that of NMR-based metabolomics, suggesting the feasibility of smartphone platform in metabolomics research. Results The smartphone metabolomics platform gave similar results to the NMR method, showing good separation between Korean and Chinese materials and correct predictability for all test samples. Conclusion With its accuracy and advantages of affordability, user-friendliness, and portability, the smartphone metabolomics platform could be applied to the authentication of other medicinal plants. Copyright © 2016 John Wiley & Sons, Ltd.
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- 2016
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26. Biological Evaluation of a New Lignan from the Roots of Rice (Oryza sativa)
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Ki Hyun Kim, Su Cheol Baek, Tae Kyoung Lee, Myoung-Sook Shin, Mun Seok Jo, Jae Sik Yu, Dahae Lee, Yoon-Joo Ko, and Ki Sung Kang
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0106 biological sciences ,0301 basic medicine ,Cell Survival ,Population ,Molecular Conformation ,Bioengineering ,Pharmacology ,Oryza ,01 natural sciences ,Biochemistry ,Plant Roots ,Lignans ,03 medical and health sciences ,chemistry.chemical_compound ,Structure-Activity Relationship ,Cell Line, Tumor ,Insulin-Secreting Cells ,Structure–activity relationship ,Humans ,Insulin ,Cytotoxicity ,education ,Molecular Biology ,Cell Proliferation ,Lignan ,education.field_of_study ,Oryza sativa ,biology ,Dose-Response Relationship, Drug ,Chemistry ,Cell growth ,food and beverages ,General Chemistry ,General Medicine ,biology.organism_classification ,Antineoplastic Agents, Phytogenic ,030104 developmental biology ,Phytochemical ,Molecular Medicine ,Drug Screening Assays, Antitumor ,010606 plant biology & botany - Abstract
LC/MS-based phytochemical analysis of an EtOH extract of the roots of rice (Oryza sativa; Gramineae), which takes a crucial role in the stable crop population in Asia, resulted in the isolation of a new lignan, oryzativol C (1), as a minor component. The chemical structure of compound 1 was unambiguously confirmed using spectroscopic evidence (including 1D- and 2D-NMR data), HR-ESI-MS, and CD data analysis. Considering the traditional medicinal efficacy of O. sativa and its importance as a food crop, compound 1 was evaluated for effects on breast cancer cell lines (MDA-MB-231) and on glucose-stimulated insulin secretion in an INS-1 pancreatic β-cell line. Compound 1 showed mild cytotoxicity toward the MDA-MB-231. Furthermore, compound 1 stimulated insulin secretion in INS-1 pancreatic β-cells without inducing cytotoxicity. These results indicate that compound 1 is an active ingredient of O. sativa that offers health benefits including inhibition of breast cancer cell proliferation and hyperglycemia control.
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- 2018
27. Observation of acetyl phosphate formation in mammalian mitochondria using real-time in-organelle NMR metabolomics
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Sunghyouk Park, He Wen, Seung-Mo Dong, Wen Jun Xu, Yoon-Joo Ko, Han Sun Kim, Jong In Yook, and In-Sun Park
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0301 basic medicine ,Pyruvate Dehydrogenase Complex ,Mitochondrion ,Oxidative Phosphorylation ,03 medical and health sciences ,Gene Knockout Techniques ,0302 clinical medicine ,Metabolomics ,Computer Systems ,Organelle ,Humans ,Nuclear Magnetic Resonance, Biomolecular ,Multidisciplinary ,Chemistry ,Metabolism ,Metabolic intermediate ,Biological Sciences ,Pyruvate dehydrogenase complex ,Genes, p53 ,HCT116 Cells ,Organophosphates ,Mitochondria ,Cytosol ,030104 developmental biology ,Biochemistry ,Acrylates ,030220 oncology & carcinogenesis ,Tumor Suppressor Protein p53 ,Two-dimensional nuclear magnetic resonance spectroscopy - Abstract
Recent studies point out the link between altered mitochondrial metabolism and cancer, and detailed understanding of mitochondrial metabolism requires real-time detection of its metabolites. Employing heteronuclear 2D NMR spectroscopy and 13C3-pyruvate, we propose in-organelle metabolomics that allows for the monitoring of mitochondrial metabolic changes in real time. The approach identified acetyl phosphate from human mitochondria, whose production has been largely neglected in eukaryotic metabolism since its first description about 70 years ago in bacteria. The kinetic profile of acetyl phosphate formation was biphasic, and its transient nature suggested its role as a metabolic intermediate. The method also allowed for the estimation of pyruvate dehydrogenase (PDH) enzyme activity through monitoring of the acetyl-CoA formation, independent of competing cytosolic metabolism. The results confirmed the positive regulation of mitochondrial PDH activity by p53, a well-known tumor suppressor. Our approach can easily be applied to other organelle-specific metabolic studies.
- Published
- 2018
28. Solution structure of the transmembrane 2 domain of the human melanocortin-4 receptor in sodium dodecyl sulfate (SDS) micelles and the functional implication of the D90N mutant
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Hyun Soo Cho, Minsup Kim, Art E. Cho, Dae-Seok Oh, Kuglae Kim, Dongju Lee, Weontae Lee, Ji Hye Yun, Yoon Joo Ko, and Young-Jin Jung
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Models, Molecular ,Magnetic Resonance Spectroscopy ,Allosteric regulation ,Mutant ,Molecular Sequence Data ,Biophysics ,Biochemistry ,Protein Structure, Secondary ,Transmembrane domain ,Melanocortin receptor ,Humans ,Amino Acid Sequence ,Obesity ,Protein secondary structure ,Micelles ,Nuclear magnetic resonance spectroscopy ,G protein-coupled receptor ,Ions ,Binding Sites ,Chemistry ,Protein Stability ,Circular Dichroism ,Sodium ,Sodium Dodecyl Sulfate ,Cell Biology ,Melanocortin 4 receptor ,Solutions ,Structural Homology, Protein ,Receptor, Melanocortin, Type 4 ,Mutant Proteins ,Salts ,Sodium ion binding ,Sodium allosteric binding - Abstract
The melanocortin receptors (MCRs) are members of the G protein-coupled receptor (GPCR) 1 superfamily with seven transmembrane (TM) domains. Among them, the melanocortin-4 receptor (MC4R) subtype has been highlighted recently by genetic studies in obese humans. In particular, in a patient with severe early-onset obesity, a novel heterozygous mutation in the MC4R gene was found in an exchange of Asp to Asn in the 90th amino acid residue located in the TM 2 domain (MC4R D90N ). Mutations in the MC4R gene are the most frequent monogenic causes of severe obesity and are described as heterozygous with loss of function. We determine solution structures of the TM 2 domain of MC4R (MC4R TM2 ) and compared secondary structure of Asp90 mutant (MC4R TM2-D90N ) in a micelle environment by nuclear magnetic resonance (NMR) spectroscopy. NMR structure shows that MC4R TM2 forms a long α-helix with a kink at Gly98. Interestingly, the structure of MC4R TM2-D90N is similar to that of MC4R TM2 based on data from CD and NMR spectrum. However, the thermal stability and homogeneity of MC4R D90N is quite different from those of MC4R. The structure from molecular modeling suggests that Asp90 2.50 plays a key role in allosteric sodium ion binding. Our data suggest that the sodium ion interaction of Asp90 2.50 in the allosteric pocket of MC4R is essential to its function, explaining the loss of function of the MC4R D90N mutant.
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- 2015
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29. Chemical constituents of the root bark of Ulmus davidiana var. japonica and their potential biological activities
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Il Kyun Lee, Hae Min So, Ki-Hyun Kim, Woo Sung Park, Sun Yeou Kim, Jae Sik Yu, Yoon-Joo Ko, Sang J. Chung, Lalita Subedi, Mi-Jeong Ahn, and Zarha Khan
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Ulmus ,Anti-Inflammatory Agents ,Nitric Oxide ,Plant Roots ,01 natural sciences ,Biochemistry ,Helicobacter Infections ,Mice ,chemistry.chemical_compound ,Ulmus davidiana ,Nerve Growth Factor ,Drug Discovery ,Ulmus davidiana var. japonica ,Animals ,Molecular Biology ,Cells, Cultured ,Inflammation ,Lignan ,chemistry.chemical_classification ,Helicobacter pylori ,biology ,Traditional medicine ,Plant Extracts ,010405 organic chemistry ,Organic Chemistry ,Glycoside ,Dihydrochalcone ,Glioma ,biology.organism_classification ,Anti-Bacterial Agents ,Rats ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Neuroprotective Agents ,chemistry ,Phytochemical ,visual_art ,Plant Bark ,visual_art.visual_art_medium ,Bark ,Microglia ,Flavanone - Abstract
The root bark of Ulmus davidiana var. japonica (Ulmaceae), commonly known as yugeunpi, has been used as a traditional Korean medicine for the treatment of gastroenteric and inflammatory disorders. As part of continuing projects to discover bioactive natural products from traditional medicinal plants with pharmacological potential, phytochemical investigation of the root bark of this plant was carried out. This led to the successful isolation of a new chromane derivative (1) and 22 known compounds: catechin derivatives (2–5), megastigmane glycoside (6), dihydrochalcone glycosides (7 and 8), flavanone glycosides (9 and 10), coumarins (11 and 12), lignan derivatives (13–17), and phenolic compounds (18–23). The structure of the new compound (1) was determined with 1D and 2D NMR spectroscopy and HR-ESIMS, and its absolute configurations were achieved by chemical reactions and the gauge-including atomic orbital (GIAO) NMR chemical shifts calculations. All the isolated compounds were evaluated for their potential biological activities including neuro-protective, anti-neuroinflammatory, and anti-Helicobacter pylori activities. Among the isolates, compounds 1, 8, and 20 displayed stronger potency by causing a greater increase in the production and the activity of nerve growth factor (NGF) in C6 glioma cells (147.04 ± 4.87, 206.27 ± 6.70, and 143.70 ± 0.88%, respectively), whereas compounds 11, 14, and 19 inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated murine microglial cells (IC50 of 18.72, 12.31, and, 21.40 µM, respectively). In addition, compounds 1, 11, 18, and 20 showed anti-H. pylori activity with MIC values of 25 or 50 µM against two strains of H. pylori 51 and 43504. These findings provide scientific evidence that supports the traditional usage of U. davidiana var. japonica root bark in the treatment of gastroenteric and inflammatory disorders.
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- 2019
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30. Cover Picture: Biological Evaluation of a New Lignan from the Roots of Rice (Oryza sativa ) (C&B 11/2018)
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Jae Sik Yu, Yoon-Joo Ko, Su Cheol Baek, Myoung-Sook Shin, Ki Sung Kang, Ki Hyun Kim, Mun Seok Jo, Dahae Lee, and Tae Kyoung Lee
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Lignan ,Oryza sativa ,Bioengineering ,General Chemistry ,General Medicine ,Biochemistry ,chemistry.chemical_compound ,chemistry ,Botany ,Molecular Medicine ,Cover (algebra) ,Poaceae ,Molecular Biology ,Biological evaluation - Published
- 2018
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31. A mechanistic study on the intramolecular ionic Diels–Alder reaction of 2-methyl-3,9,11-tridecatriene-2-ol and 2,11-dimethyl-1,3,9,11-dodecatetraene
- Author
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Yoon-Joo Ko, Seung-Bo Shim, and Jung-Hyu Shin
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Cyclohexane ,Chemistry ,Organic Chemistry ,Ionic bonding ,Regioselectivity ,Carbocation ,Biochemistry ,Medicinal chemistry ,chemistry.chemical_compound ,Mechanism (philosophy) ,Intramolecular force ,Drug Discovery ,Organic chemistry ,Stepwise reaction ,Diels–Alder reaction - Abstract
Intramolecular ionic Diels–Alder reaction of 2-methyl-3,9,11-tridecatriene-2-ol (1) was studied under acidic conditions. Treatment of 2-methyl-3,9,11-tridecatriene-2-ol (1) with trifluoromethanesulfonic acid yielded 7-methyl-8-isopropenyl-1,2,3,4,4aR∗,7R∗,8R∗,8aS∗-octahydronaphthalene (4) and (1Z)-1-((E)-but-2-enylidene)-2-(2-methylpropenyl)cyclohexane (5) through regioselective intramolecular ionic Diels–Alder reaction. The reaction appeared to proceed partly through a stepwise mechanism involving a carbocation intermediate. However, a concerted pathway rather than a stepwise one is suggested to be involved in the acid-catalyzed intramolecular Diels–Alder reaction of 2,11-dimethyl-1,3,9,11-dodecatetraene (13).
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- 2007
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32. Self-assembly of octacyano-biscavitand by metal ligand interaction: incorporation of container unit in polymer back bone
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Chaesang Ihm, Yoon-Joo Ko, Jung-Hyu Shin, and Kyungsoo Paek
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chemistry.chemical_classification ,Ligand ,Organic Chemistry ,Polymer ,Container (type theory) ,Biochemistry ,Metal ,Crystallography ,chemistry ,visual_art ,Drug Discovery ,visual_art.visual_art_medium ,Proton NMR ,Self-assembly - Abstract
Octacyano-biscavitand 2 was synthesized and the formation of its self-assembled oligomeric coordination molecular capsule 4 with Pd(dppp)OTf 2 was studied by 1 H NMR, PGSE NMR, and SEM. Oligomeric capsule 4 having container units in the backbone was chopped down to hetero-coupled biscapsules 5 by pyridinocavitand 3 .
- Published
- 2006
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33. Facile synthesis of 2-O-iodoacetyl protected glycosyl iodides: useful precursors of 1--2-linked 1,2-trans-glycosides
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Seung-Bo Shim, Yoon-Joo Ko, and Jung-Hyu Shin
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chemistry.chemical_classification ,Anomer ,Molecular Structure ,Organic Chemistry ,Iodide ,Acetal ,Ketene ,Glycoside ,Stereoisomerism ,Biochemistry ,Combinatorial chemistry ,chemistry.chemical_compound ,chemistry ,Thiourea ,Yield (chemistry) ,Combinatorial Chemistry Techniques ,Glycosyl ,Glycosides ,Physical and Theoretical Chemistry ,Hydrocarbons, Iodinated - Abstract
The preparation and utilization of novel iodide glycosyl donors, 2-O-iodoacetyl-glycopyranosyl iodides, is described. The mechanism for the reaction of iodine with carbohydrate cyclic ketene acetal was investigated through low-temperature NMR experiments. 2-O-Iodoacetyl-glycopyranosyl iodides can serve as effective glycosyl donors giving 2-O-iodoacetyl 1,2-trans-glycosides in high yields and excellent stereoselectivities. The 2-O-iodoacetyl group was removed selectively with thiourea to afford 2-hydroxy 1,2-trans-glycosides in high yield without affecting other protecting groups and anomeric configurations.
- Published
- 2009
34. Synthesis and in vitro photodynamic activities of water-soluble fluorinated tetrapyridylporphyrins as tumor photosensitizers
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Jung-Hyu Shin, Kyung-Tae Lee, Minseok Kang, Yoon-Joo Ko, Jongmin Park, Seung Bum Park, and Kyung-Jin Yun
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Porphyrins ,Cell Survival ,Photochemistry ,medicine.medical_treatment ,Clinical Biochemistry ,Pharmaceutical Science ,Photodynamic therapy ,Antineoplastic Agents ,Biochemistry ,HeLa ,chemistry.chemical_compound ,Drug Discovery ,polycyclic compounds ,medicine ,Humans ,Photosensitizer ,MTT assay ,Cytotoxicity ,Molecular Biology ,Photosensitizing Agents ,biology ,Organic Chemistry ,Water ,Fluorine ,biology.organism_classification ,Photobleaching ,Porphyrin ,In vitro ,chemistry ,Photochemotherapy ,Solubility ,Molecular Medicine ,Drug Screening Assays, Antitumor ,HeLa Cells - Abstract
A series of water-soluble fluorinated cationic porphyrins were designed, synthesized, and characterized. In vitro photocytotoxicity of these compounds was evaluated by MTT assay on HeLa cells. Their photocytotoxicity was dependent on the positions of the cations and the fluorines in the pyridine ring, and 5,10,15,20-tetrakis-(N-methyl-2-fluoro-pyridin-3-yl)-porphyrin (8) showed the most potent photo-induced cytotoxicity without photobleaching. PDT-induced ROS inside HeLa cells was measured with flow cytometry using ROS-sensitive fluorometric probe, 2,7-dichlorofluororescin (DCF), which revealed high correlations of ROS with cellular cytotoxicity. FACS analysis shows that PDT with porphyrin 8 induced apoptosis in HeLa cells. In summary, efficient generation of ROS, biological effectiveness, and good photostability of porphyrin 8 indicate its potential application in photodynamic therapy (PDT) in the near future.
- Published
- 2006
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