89 results on '"Bong Sik Yun"'
Search Results
2. 5-Hydroxymaltol Derived from Beetroot Juice through Lactobacillus Fermentation Suppresses Inflammatory Effect and Oxidant Stress via Regulating NF-kB, MAPKs Pathway and NRF2/HO-1 Expression
- Author
-
Su-Lim Kim, Bong-Sik Yun, Hack Sun Choi, Yu-Chan Ko, and Dong-Sun Lee
- Subjects
5-hydroxymaltol ,Physiology ,medicine.medical_treatment ,Clinical Biochemistry ,Inflammation ,RM1-950 ,Biochemistry ,Nitric oxide ,Nrf-2 ,chemistry.chemical_compound ,medicine ,Protein kinase A ,Molecular Biology ,chemistry.chemical_classification ,Reactive oxygen species ,Lactobacillus fermentation ,biology ,lipopolysaccharide ,Cell Biology ,Molecular biology ,cytokines ,Heme oxygenase ,Nitric oxide synthase ,Cytokine ,chemistry ,inflammation ,biology.protein ,Therapeutics. Pharmacology ,medicine.symptom ,Signal transduction - Abstract
Inflammation is the first response of the immune system against bacterial pathogens. This study isolated and examined an antioxidant derived from Lactobacillus fermentation products using cultured media with 1% beet powder. The antioxidant activity of the beet culture media was significantly high. Antioxidant activity-guided purification and repeated sample isolation yielded an isolated compound, which was identified as 5-hydoxymaltol using nuclear magnetic resonance spectrometry. We examined the mechanism of its protective effect on lipopolysaccharide (LPS)-induced inflammation of macrophages. 5-Hydroxymaltol suppressed nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. It also suppressed tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and inducible nitric oxide synthase (iNOS) in the messenger RNA and protein levels in LPS-treated RAW 264.7 cells. Moreover, it suppressed LPS-induced nuclear translocation of NF-κB (p65) and mitogen-activated protein kinase activation. Furthermore, 5-hydroxymaltol reduced LPS-induced reactive oxygen species (ROS) production as well as increased nuclear factor erythroid 2–related factor 2 and heme oxygenase 1 expression. Overall, this study found that 5-hydroxymaltol has anti-inflammatory activities in LPS-stimulated RAW 264.7 macrophage cells based on its inhibition of pro-inflammatory cytokine production depending on the nuclear factor κB signaling pathway, inhibition of LPS-induced reactive oxygen species production, inhibition of LPS-induced mitogen-activated protein kinase induction, and induction of the nuclear factor erythroid 2–related factor 2/heme oxygenase 1 signaling pathway. Our data showed that 5-hydroxymaltol may be an effective compound for treating inflammation-mediated diseases.
- Published
- 2021
- Full Text
- View/download PDF
3. Neuraminidase Inhibitors from the Fruiting Body of Glaziella splendens
- Author
-
In-Kyoung Lee, Ji-Yul Kim, Bong-Sik Yun, Lee Su Ha, Dae-Won Ki, and E-Eum Woo
- Subjects
chemistry.chemical_classification ,0303 health sciences ,biology ,Neuraminidase inhibitor ,medicine.drug_class ,Glycosidic bond ,Microbiology ,lcsh:QK1-989 ,Glaziella splendens ,030308 mycology & parasitology ,Azaphilone ,Research Note ,03 medical and health sciences ,Infectious Diseases ,Biochemistry ,chemistry ,lcsh:Botany ,biology.protein ,medicine ,Neuraminidase ,030304 developmental biology - Abstract
Neuraminidase (NA) cleaves the glycosidic bond linkages of sialic acids to release the mature virions from infected cells and has been an attractive therapeutic target for anti-influenza agents. In our ongoing investigation of NA inhibitors in mushroom extracts, we found that the extract the fruiting body of Glaziella splendens potently inhibited neuraminidase. The fruiting bodies of G. splendens were extracted and partitioned successively with hexane, ethyl acetate, and butanol. The ethyl acetate soluble-layer was subjected to silica gel and Sephadex LH-20 column chromatographies, and MPLC to obtain five compounds (1–5). Their structures were determined by spectroscopic methods. NA inhibitory activity of these compounds was evaluated using NAs from recombinant rvH1N1, H3N2, and H5N1 influenza A viruses. One compound (1) was elucidated as a new azaphilone derivative, and four compounds (2–5) were identified as entonaemin A, comazaphilone D, rubiginosin A, and entonaemin B, respectively. Compounds 3 and 4 showed considerable inhibitory activity against three types of neuraminidases with the IC50 values of 30.9, 41.8, and 35.7 µM for 3 and 46.5, 50.4, and 29.9 µM for 4, respectively. This study reveals that the fruiting bodies of G. splendens possess azaphilone derivatives with the NA inhibitory activity. This is the first report on the isolation of neuraminidase inhibitors from the fruiting bodies of G. splendens.
- Published
- 2019
- Full Text
- View/download PDF
4. Caudatin Isolated from Cynanchum auriculatum Inhibits Breast Cancer Stem Cell Formation via a GR/YAP Signaling
- Author
-
Xing Zhen, Ren Liu, Yu-Chan Ko, Hack Sun Choi, Ji-Hyang Kim, Dong-Sun Lee, Su-Lim Kim, and Bong-Sik Yun
- Subjects
0301 basic medicine ,cancer stem cells ,Population ,Cell ,lcsh:QR1-502 ,Biochemistry ,lcsh:Microbiology ,Metastasis ,03 medical and health sciences ,0302 clinical medicine ,SOX2 ,Cancer stem cell ,medicine ,caudatin ,education ,Molecular Biology ,education.field_of_study ,Tumor microenvironment ,Cynanchum auriculatum ,biology ,Chemistry ,CD44 ,glucocorticoid receptor (GR) ,mammospheres ,biology.organism_classification ,medicine.disease ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,biology.protein ,Cancer research ,YAP - Abstract
In the complex tumor microenvironment, cancer stem cells (CSCs), a rare population of cells, are responsible for malignant tumor initiation, metastasis, drug resistance and recurrence. Controlling breast CSCs (BCSCs) using natural compounds is a novel potential therapeutic strategy for clinical cancer treatment. In this study, a mammosphere assay-guided isolation protocol including silica gel, a C18 column, gel filtration, and high-pressure liquid chromatography was used to isolate an inhibitory compound from Cynanchum auriculatum extracts. The isolated inhibitory compound was identified as caudatin. Caudatin inhibited breast cancer cell proliferation, mammosphere formation and tumor growth. Caudatin decreased the CD44+/CD24- and aldehyde dehydrogenase+ cell proportions and the levels of c-Myc, Oct4, Sox2, and CD44. Caudatin induced ubiquitin (Ub)-dependent glucocorticoid receptor (GR) degradation and blocked subsequent Yes-associated protein (YAP) nuclear accumulation and target gene transcription signals in BCSCs. These results show that the GR/YAP signaling pathway regulates BCSC formation and that caudatin may be a potential chemopreventive agent that targets breast cancer cells and CSCs.
- Published
- 2020
- Full Text
- View/download PDF
5. Machilin D, a Lignin Derived from Saururus chinensis, Suppresses Breast Cancer Stem Cells and Inhibits NF-κB Signaling
- Author
-
Bong-Sik Yun, Ji-Hyang Kim, Su-Lim Kim, Xing Zhen, Dong-Sun Lee, Hack Sun Choi, and Ren Liu
- Subjects
0301 basic medicine ,Magnetic Resonance Spectroscopy ,lcsh:QR1-502 ,Aldehyde dehydrogenase ,Biochemistry ,lcsh:Microbiology ,Mass Spectrometry ,NF-κB ,Metastasis ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Chromatography, High Pressure Liquid ,biology ,NF-kappa B ,mammospheres ,Gene Expression Regulation, Neoplastic ,Hyaluronan Receptors ,030220 oncology & carcinogenesis ,machilin D ,MCF-7 Cells ,Neoplastic Stem Cells ,Female ,Stem cell ,Powders ,Signal Transduction ,Active Transport, Cell Nucleus ,Mice, Nude ,Breast Neoplasms ,Aldehyde Dehydrogenase 1 Family ,Lignans ,Article ,03 medical and health sciences ,Cancer stem cell ,Cell Line, Tumor ,Saururaceae ,medicine ,Animals ,Humans ,Molecular Biology ,Interleukin-6 ,Plant Extracts ,CD44 ,Interleukin-8 ,Cancer ,CD24 Antigen ,medicine.disease ,Molecular biology ,breast cancer stem cells (BCSCs) ,030104 developmental biology ,chemistry ,Sephadex ,biology.protein ,Chromatography, Thin Layer ,Neoplasm Transplantation - Abstract
Cancer stem cells are responsible for breast cancer initiation, metastasis, and relapse. Targeting breast cancer stem cells (BCSCs) using phytochemicals is a good strategy for the treatment of cancer. A silica gel, a reversed-phase C18 column (ODS), a Sephadex LH-20 gel, thin layer chromatography, and high-performance liquid chromatography (HPLC) were used for compound isolation from Saururus chinensis extracts. The isolated compound was identified as machilin D by mass spectrometry and nuclear magnetic resonance (NMR). Machilin D inhibited the growth and mammosphere formation of breast cancer cells and inhibited tumor growth in a xenograft mouse model. Machilin D reduced the proportions of CD44+/CD24- and aldehyde dehydrogenase 1 (ALDH1)-positive cells. Furthermore, this compound reduced the nuclear localization of the NF-&kappa, B protein and decreased the IL-6 and IL-8 secretion in mammospheres. These results suggest that machilin D blocks IL-6 and IL-8 signaling and induces CSC death and thus may be a potential agent targeting BCSCs.
- Published
- 2020
6. Oxalic Acid from Lentinula edodes Culture Filtrate: Antimicrobial Activity on Phytopathogenic Bacteria and Qualitative and Quantitative Analyses
- Author
-
A-Min Kwak, Sang-Yeop Lee, Bong-Sik Yun, In-Kyoung Lee, and Hee-Wan Kang
- Subjects
0106 biological sciences ,0301 basic medicine ,Ralstonia solanacearum ,Chromatography ,biology ,Oxalic acid ,food and beverages ,biology.organism_classification ,Antimicrobial ,01 natural sciences ,Microbiology ,High-performance liquid chromatography ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Infectious Diseases ,Lentinula ,Column chromatography ,Biochemistry ,chemistry ,010608 biotechnology ,Antibacterial activity ,Bacteria - Abstract
The culture filtrate of Lentinula edodes shows potent antimicrobial activity against the plant pathogenic bacteria Ralstonia solanacearum. Bioassay-guided fractionation was conducted using Diaion HP-20 column chromatography, and the insoluble active compound was not adsorbed on the resin. Further fractionation by high-performance liquid chromatography (HPLC) suggested that the active compounds were organic acids. Nine organic acids were detected in the culture filtrate of L. edodes; oxalic acid was the major component and exhibited antibacterial activity against nine different phytopathogenic bacteria. Quantitative analysis by HPLC revealed that the content of oxalic acid was higher in the water extract from spent mushroom substrate than in liquid culture. This suggests that the water extract of spent L. edodes substrate is an eco-friendly control agent for plant diseases.
- Published
- 2016
- Full Text
- View/download PDF
7. Characterization of Neuraminidase Inhibitors in Korean Papaver rhoeas Bee Pollen Contributing to Anti-Influenza Activities In Vitro
- Author
-
Ji-Yul Kim, Yoon-Ju Lee, Dae-Won Kim, Hwa Jung Choi, In-Kyoung Lee, Bong-Sik Yun, Byung Soon Hwang, and E-Eum Woo
- Subjects
0301 basic medicine ,Magnetic Resonance Spectroscopy ,medicine.drug_class ,Drug Evaluation, Preclinical ,Neuraminidase ,Pharmaceutical Science ,Antiviral Agents ,Madin Darby Canine Kidney Cells ,Analytical Chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Dogs ,Influenza A Virus, H1N1 Subtype ,Zanamivir ,Non-competitive inhibition ,Drug Discovery ,Papaveraceae ,medicine ,Animals ,Papaver ,Enzyme Inhibitors ,Flavonoids ,Pharmacology ,Dose-Response Relationship, Drug ,Influenza A Virus, H5N1 Subtype ,Molecular Structure ,biology ,Neuraminidase inhibitor ,Influenza A Virus, H3N2 Subtype ,Alkaloid ,Organic Chemistry ,Bees ,biology.organism_classification ,030104 developmental biology ,Complementary and alternative medicine ,Biochemistry ,chemistry ,Bee pollen ,biology.protein ,Pollen ,Molecular Medicine ,Luteolin ,medicine.drug - Abstract
The active constituents of Korean Papaver rhoeas bee pollen conferring neuraminidase inhibitory activities (H1N1, H3N2, and H5N1) were investigated. Six flavonoids and one alkaloid were isolated and characterized by nuclear magnetic resonance and mass spectrometry data. These included kaempferol-3-sophoroside (1), kaempferol-3-neohesperidoside (2), kaempferol-3-sambubioside (3), kaempferol-3-glucoside (4), quercetin-3-sophoroside (5), luteolin (6), and chelianthifoline (7). All compounds showed neuraminidase inhibitory activities with IC50 values ranging from 10.7 to 151.1 µM. The most potent neuraminidase inhibitor was luteolin, which was the dominant content in the ethyl acetate fraction. All tested compounds displayed noncompetitive inhibition of H3N2 neuraminidase. Furthermore, compounds 1-7 all reduced the severity of virally induced cytopathic effects as determined by the Madin-Darby canine kidney cell-based assay showing antiviral activity with IC50 values ranging from 10.7 to 33.4 µM (zanamivir: 58.3 µM). The active compounds were quantified by high-performance liquid chromatography, and the total amount of compounds 1-7 made up about 0.592 g/100 g bee pollen, contributing a rich resource of a natural antiviral product.
- Published
- 2016
- Full Text
- View/download PDF
8. Differential Modulation of Lipopolysaccharide-Induced Inflammatory Cytokine Production by and Antioxidant Activity of Fomentariol in RAW264.7 Cells
- Author
-
Bong Sik Yun, Myeong Seok Lee, Sang-Myeong Lee, Dong Won Seo, and Young-Joo Yi
- Subjects
0106 biological sciences ,Fomes fomentarius ,Lipopolysaccharide ,medicine.medical_treatment ,Pharmacology ,01 natural sciences ,Microbiology ,Nitric oxide ,RAW264.7 cells ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Immune system ,Downregulation and upregulation ,010608 biotechnology ,Extracellular ,medicine ,Fomentariol ,LPS-induced inflammatory responses ,biology ,biology.organism_classification ,ERK signaling pathway ,Infectious Diseases ,Cytokine ,chemistry ,Biochemistry ,Tumor necrosis factor alpha ,Research Article ,030215 immunology - Abstract
Medicinal mushrooms have been used worldwide to treat cancer and modulate the immune system. Over the last several years, there has been increasing interest in isolating bioactive compounds from medicinal mushrooms and evaluating their health beneficial effects. Fomes fomentarius is used in traditional oriental medicine and is known to possess antioxidant, anti-inflammatory, antidiabetic, and antitumor effects. In the present study, we isolated fomentariol from Fomes fomentarius and investigated its anti-inflammatory effect in murine macrophages (RAW264.7 cells) stimulated with lipopolysaccharides. Fomentariol inhibited the production of nitric oxide and intracellular reactive oxygen species triggered by lipopolysaccharides. Interestingly, fomentariol differentially regulated cytokine production triggered by lipopolysaccharides. Fomentariol effectively suppressed the production of interleukin-1β and interleukin-6 but not tumor necrosis factor-α. The inhibitory effect of fomentariol against nitric oxide, interleukin-1β, and interleukin-6 production was possibly mediated by downregulation of the extracellular signal-regulated kinase signaling pathway. Taken together, our results suggest that fomentariol differentially modulated inflammatory responses triggered by lipopolysaccharides in macrophages and is one of the bioactive compounds that mediate the physiological effects of Fomes fomentarius.
- Published
- 2015
- Full Text
- View/download PDF
9. Anti-influenza activities of polyphenols from the medicinal mushroom Phellinus baumii
- Author
-
Hwa Jung Choi, Bong-Sik Yun, In-Kyoung Lee, and Byung Soon Hwang
- Subjects
viruses ,Clinical Biochemistry ,Neuraminidase ,Pharmaceutical Science ,Mdck cell ,Phellinus baumii ,Hypholomine B ,Antiviral Agents ,Biochemistry ,Madin Darby Canine Kidney Cells ,Microbiology ,chemistry.chemical_compound ,Dogs ,Influenza A Virus, H1N1 Subtype ,Medicinal mushroom ,Cytopathogenic Effect, Viral ,Drug Discovery ,Animals ,Fruiting Bodies, Fungal ,Molecular Biology ,Cytopathic effect ,Medicine, East Asian Traditional ,Dose-Response Relationship, Drug ,Influenza A Virus, H5N1 Subtype ,Traditional medicine ,Basidiomycota ,Influenza A Virus, H3N2 Subtype ,Davallialactone ,Organic Chemistry ,Polyphenols ,virus diseases ,Orthomyxoviridae ,Kinetics ,chemistry ,Polyphenol ,Hispidin ,Molecular Medicine ,Agaricales - Abstract
Five polyphenols were isolated from the ethanolic extract of the fruiting bodies of Phellinus baumii. These compounds were identified by various spectroscopic methods as hispidin, hypholomine B, inoscavin A, davallialactone, and phelligridin D. All compounds inhibited noncompetitively H1N1, H5N1, and H3N2 neuraminidase activity and reduced the amount of virally-induced cytopathic effect (CPE) according to an MDCK cell-based assay.
- Published
- 2015
- Full Text
- View/download PDF
10. New Glabretal Triterpenes from the Immature Fruits of Poncirus trifoliata and Their Selective Cytotoxicity
- Author
-
In-Kyoung Lee, Bong-Sik Yun, Jin-Won Kwon, Hae-Ryong Park, Ae-Ran Choi, and E. Eum Woo
- Subjects
Cell growth ,Chemistry ,Electrospray ionization ,General Chemistry ,General Medicine ,Selective cytotoxicity ,medicine.disease ,medicine.disease_cause ,Terpene ,Biochemistry ,Pancreatic cancer ,Drug Discovery ,medicine ,Structure–activity relationship ,Stress conditions ,Oxidative stress - Abstract
Two new glabretal triterpenes, pancastatins A (1) and B (2), were isolated from the immature fruits of Poncirus trifoliata. Their chemical structures were elucidated by spectroscopic analyses including one- and two-dimensional NMR and high-resolution electrospray ionization mass spectrometry. Compounds 1 and 2 exhibited selective cytotoxicity against PANC-1 pancreatic cancer cells under low-glucose stress conditions.
- Published
- 2015
- Full Text
- View/download PDF
11. Bile Acid 7α-Dehydroxylating Gut Bacteria Secrete Antibiotics that Inhibit Clostridium difficile: Role of Secondary Bile Acids
- Author
-
Spencer C. Harris, In-Kyoung Lee, Keiichi Matsuzaki, Genta Kakiyama, Hae-Ki Min, Jasmohan S. Bajaj, Phillip B. Hylemon, Jason D. Kang, Christopher J. Myers, Bong-Sik Yun, Megumi Furukawa, and Huiping Zhou
- Subjects
Pharmacology ,Lithocholic acid ,Bile acid ,010405 organic chemistry ,medicine.drug_class ,Clinical Biochemistry ,Antibiotics ,Deoxycholic acid ,Cholic acid ,Clostridium difficile ,Biology ,medicine.disease ,digestive system ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Microbiology ,chemistry.chemical_compound ,[Clostridium] scindens ,chemistry ,Drug Discovery ,medicine ,Molecular Medicine ,Molecular Biology ,Dysbiosis - Abstract
Summary Clostridium scindens biotransforms primary bile acids into secondary bile acids, and is correlated with inhibition of Clostridium difficile growth in vivo. The aim of the current study was to determine how C. scindens regulates C. difficile growth in vitro and if these interactions might relate to the regulation of gut microbiome structure in vivo. The bile acid 7α-dehydroxylating gut bacteria, C. scindens and C. sordellii, were found to secrete the tryptophan-derived antibiotics, 1-acetyl-β-carboline and turbomycin A, respectively. Both antibiotics inhibited growth of C. difficile and other gut bacteria. The secondary bile acids, deoxycholic acid and lithocholic acid, but not cholic acid, enhanced the inhibitory activity of these antibiotics. These antibiotics appear to inhibit cell division of C. difficile. The results help explain how endogenously synthesized antibiotics and secondary bile acids may regulate C. difficile growth and the structure of the gut microbiome in health and disease.
- Published
- 2019
- Full Text
- View/download PDF
12. New p-terphenyls from the fruiting bodies of Pseudomerulius curtisii and their antioxidant activity
- Author
-
Bong-Sik Yun, In-Kyoung Lee, and Byung Soon Hwang
- Subjects
0301 basic medicine ,Antifungal ,Antioxidant ,medicine.drug_class ,medicine.medical_treatment ,Beta-lactam ,03 medical and health sciences ,chemistry.chemical_compound ,Terphenyl Compounds ,Drug Discovery ,Botany ,medicine ,Fruiting Bodies, Fungal ,Pharmacology ,Molecular Structure ,biology ,Pseudomerulius curtisii ,Basidiomycota ,Oxidation reduction ,biology.organism_classification ,030104 developmental biology ,chemistry ,Biochemistry ,Reactive Oxygen Species ,Oxidation-Reduction - Abstract
New p -terphenyls from the fruiting bodies of Pseudomerulius curtisii and their antioxidant activity
- Published
- 2015
- Full Text
- View/download PDF
13. Enantioselective induction of SIRT1 gene by syringaresinol from Panax ginseng berry and Acanthopanax senticosus Harms stem
- Author
-
Bong Sik Yun, Jiyong Park, Si Young Cho, Sang Jun Lee, Jeong Un Kim, Hyun Hee Kim, and Hyun Woo Park
- Subjects
Syringaresinol ,Clinical Biochemistry ,Panax ,Pharmaceutical Science ,Eleutherococcus ,Berry ,Real-Time Polymerase Chain Reaction ,Biochemistry ,Lignans ,chemistry.chemical_compound ,Ginseng ,Sirtuin 1 ,Drug Discovery ,Gene expression ,Botany ,Human Umbilical Vein Endothelial Cells ,Humans ,RNA, Messenger ,Furans ,Promoter Regions, Genetic ,Molecular Biology ,Traditional medicine ,Plant Extracts ,Reverse Transcriptase Polymerase Chain Reaction ,Chemistry ,Forkhead Box Protein O3 ,Organic Chemistry ,Enantioselective synthesis ,food and beverages ,Forkhead Transcription Factors ,Stereoisomerism ,Biological activity ,Surface Plasmon Resonance ,Fruit ,Molecular Medicine ,Enantiomer ,SIRT1 Gene - Abstract
Syringaresinol exists either exclusively as one enantiomer or enantiomeric mixtures in plant foods. We found that (+)-syringaresinol, but not (-)-syringaresinol, upregulates silent information regulator two ortholog 1 (SIRT1) gene expression, and thus, Panax ginseng berry with predominantly high contents of (+)-syringaresinol exhibits higher activity in inducing SIRT1 gene expression than Acanthopanax senticosus Harms stem with almost equal proportion of the two enantiomers. These findings highlight the importance of the absolute configuration of syringaresinol for the biological activity.
- Published
- 2015
- Full Text
- View/download PDF
14. Davallialactone from Mushroom Reduced Premature Senescence and Inflammation on Glucose Oxidative Stress in Human Diploid Fibroblast Cells
- Author
-
Bong-Sik Yun, Young Hee Lee, Govinda Bhattarai, Pyoung-Han Hwang, Ho-Keun Yi, Usha Paudel, and Tae-Ki Yang
- Subjects
Senescence ,Antioxidant ,medicine.medical_treatment ,Inflammation ,Biology ,medicine.disease_cause ,Pathogenesis ,Glucose Oxidase ,Lactones ,chemistry.chemical_compound ,medicine ,Humans ,Fibroblast ,Protein kinase A ,Cells, Cultured ,Cellular Senescence ,Basidiomycota ,Davallialactone ,General Chemistry ,Fibroblasts ,beta-Galactosidase ,Diploidy ,Cell biology ,Oxidative Stress ,Glucose ,medicine.anatomical_structure ,chemistry ,Biochemistry ,medicine.symptom ,Reactive Oxygen Species ,General Agricultural and Biological Sciences ,Oxidative stress - Abstract
Mushrooms are both food and a source of natural compounds of biopharmaceutical interest. The purpose of this study was to clarify whether davallialactone from mushroom extract affected the pathogenesis of hyperglycemia oxidative stress and the aging process in human diploid fibroblast (HDF) cells. The high-glucose state with glucose oxidase resulted in glucose oxidative stress, induction of inflammatory molecules, dysfunction of antioxidant molecules, and activation of mitogen-activated protein kinase (MAPKs) and its downstream signaling in old HDF cells. The exposure of glucose oxidative stress in middle-stage cells led to stress-induced premature senescence (SIPS) via senescence-associated β-galactosidase (SA β-gal) activity and displayed replicative senescence phenomena. However, davallialactone reduces the pathogenesis of glucose oxidative stress and the aging process through down-regulation of SA β-gal activity. These results strongly suggest that natural compounds, especially mushroom extract davallialactone, improve the pathogenesis of glucose oxidative stress and the aging process. Hence, davallialactone has potential in the treatment of diabetes mellitus or age-related disease complications.
- Published
- 2013
- Full Text
- View/download PDF
15. Anti-inflammatory activity of the active components from the roots ofCosmos bipinnatusin lipopolysaccharide-stimulated RAW 264.7 macrophages
- Author
-
Wahn-Soo Choi, Si-Kwan Kim, Bong-Sik Yun, Soyoung Kim, Jun-Sik Yoo, Hyun-Soo Jeon, and Sang-Hyun Sohn
- Subjects
Lipopolysaccharides ,Lipopolysaccharide ,medicine.drug_class ,Anti-Inflammatory Agents ,Inflammation ,Plant Science ,Asteraceae ,Cosmos bipinnatus ,Pharmacology ,Sesquiterpene lactone ,Plant Roots ,Biochemistry ,Anti-inflammatory ,Cell Line ,Analytical Chemistry ,Mice ,chemistry.chemical_compound ,medicine ,Animals ,Prostaglandin E2 ,IC50 ,chemistry.chemical_classification ,integumentary system ,biology ,Organic Chemistry ,biology.organism_classification ,Nitric oxide synthase ,chemistry ,biology.protein ,medicine.symptom ,medicine.drug - Abstract
We isolated a sesquiterpene lactone from the methanol extract of the roots of Cosmos bipinnatus, namely, MDI (a mixture of dihydrocallitrisin and isohelenin). The anti-inflammatory activity of MDI was evaluated using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. MDI significantly inhibited the expression of inducible nitric oxide synthase and cyclooxygenase-2. Consistent with these results, the production of NO and prostaglandin E2 (PGE2) was suggested to be suppressed by MDI in a concentration-dependent manner (IC50 value was 0.94 and 2.88 µg mL(-1) for NO and PGE2, respectively). In addition, MDI significantly inhibited the expressions of pro-inflammatory cytokines such as IL-1β, IL-6, IFN-γ and TNF-α. Furthermore, MDI attenuated DNA-binding activity of NF-κB by inhibiting the phosphorylation of IκB. These results indicate that MDI isolated from the roots of C. bipinnatus shows anti-inflammatory activity in LPS-stimulated murine macrophages by modulating the NF-κB pathway.
- Published
- 2013
- Full Text
- View/download PDF
16. Determination of singlet oxygen quenching and antioxidant activity of Bieckols isolated from the brown alga Eisenia bicyclis
- Author
-
Bong-Sik Yun, Dai-Il Hwang, Oh-Oun Kwon, Tae-Hyung Kwon, You-Jeong Kim, In-Kyoung Lee, Choong-Gon Kim, Min-Jeong Kim, Hwa-Jin Suh, Nyun-Ho Park, and Tae Wan Kim
- Subjects
chemistry.chemical_classification ,Reactive oxygen species ,Antioxidant ,ABTS ,Quenching (fluorescence) ,biology ,Chemistry ,DPPH ,medicine.medical_treatment ,General Chemistry ,biology.organism_classification ,Biochemistry ,Industrial and Manufacturing Engineering ,Brown algae ,chemistry.chemical_compound ,Eisenia ,medicine ,Organic chemistry ,Trolox ,Food science ,Food Science ,Biotechnology - Abstract
In this study, we determined 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities as well as the reducing power for screening of antioxidant activity of bieckols in Eisenia bicyclis (Kjellamn) Setchell (E. bicyclis). The compounds 6,6′-bieckol, 6,8′-bieckol and 8,8′-bieckol are representative members of the phlorotannins family. The isolated bieckols displayed markedly strong DPPH and ABTS radical scavenging effects when compared to those of positive controls (BHA and Trolox). These bieckols were also found to have significant reducing power. The isolated bieckols (6,6′-bieckol, 6,8′-bieckol and 8,8′-bieckol) were found to effectively suppress the detrimental effects of 1O2 on type-II photosensitization. The concentrations required to exert a 50 % quenching effect on 1O2 (QC50) were found to be 30.7, 35.7 and 49.4 μM for 6,6′-bieckol, 6,8′-bieckol and 8,8′-bieckol, respectively. Interestingly, all these bieckols were found to be superior to histidine (5.9 mM), a well-known 1O2 quencher. These results suggested that brown algae phlorotannins, and bieckols in particular, may play an important role in protecting marine organisms against sunlight damage by eliminating 1O2. This knowledge may contribute to the development of natural bioactive products with potential applications in reducing photo-produced oxidative damage involving reactive oxygen species in living organisms.
- Published
- 2013
- Full Text
- View/download PDF
17. The Antioxidant Property of Pachymic Acid Improves Bone Disturbance against AH Plus–induced Inflammation in MC-3T3 E1 Cells
- Author
-
Bong Sik Yun, Govinda Bhattarai, Ho Keun Yi, Young Hee Lee, Tae Gun Kim, In Kyoung Lee, and Nan Hee Lee
- Subjects
Materials science ,Antioxidant ,Cell Survival ,medicine.medical_treatment ,Interleukin-1beta ,Anti-Inflammatory Agents ,Inflammation ,Nitric Oxide ,Antioxidants ,Nitric oxide ,Proinflammatory cytokine ,Root Canal Filling Materials ,Mice ,chemistry.chemical_compound ,medicine ,Animals ,Viability assay ,Bone Resorption ,Cytotoxicity ,Receptor ,General Dentistry ,Osteoblasts ,Epoxy Resins ,Tumor Necrosis Factor-alpha ,3T3 Cells ,Molecular biology ,Triterpenes ,Oxidative Stress ,chemistry ,Biochemistry ,Tumor necrosis factor alpha ,Inflammation Mediators ,medicine.symptom ,Reactive Oxygen Species - Abstract
Introduction The cytotoxicity of resin-based sealer is influential on the inflammatory reaction and cell survival for oral periapical cells. In this study, pachymic acid as an antioxidant was investigated for the improvement of bone disturbance against AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany)–induced inflammation in MC-3T3 E1 cells. Methods AH Plus was prepared according to the manufacturer's instructions. Using mouse osteoblast cells (MC-3T3 E1), a specimen of AH Plus was eluted with the culture medium for 1 day and was diluted by 30%. The cellular cytotoxicity and reactive oxygen species formation was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and 2′,7′-dichlorodihydrofluorescein diacetate with fluorescence-activated cell sorting. The secretion of proinflammatory cytokines was determined by an enzyme-linked immunosorbent assay, and the expression of inflammatory and osteogenic molecules was determined by immunoblotting. Results Cells with AH Plus elutes showed a decrease of cell viability and ALP activity. However, pachymic acid and N-acetyl-L-cysteine (control antioxidant) restored cell viability and ALP activity damaged by AH plus. The secretion of nitric oxide, tumor necrosis factor α, and interleukin-1β were increased in AH Plus–stimulated MC-3T3 E1 cells, but pachymic acid suppressed its production. Furthermore, pachymic acid reduced the receptor activator of nuclear factor-κB ligand, cyclooxygenase-2, matrix metalloproteinase-2 and -9, increased bone morphogenetic protein-2 and -7, and runt-related transcription factor 2 despite AH Plus stimuli. In addition, pachymic acid affected the removal effect of reactive oxygen species formation as did N-acetyl-L-cysteine. More importantly, pachymic acid inhibited nuclear factor-κB translocation. Conclusions The property of pachymic acid can mitigate the unfavorable conditions induced by AH Plus stimuli. Therefore, the use of pachymic acid is suggested to prevent the complications of oral diseases such as inflammation and alveolar destruction of the oral cavity.
- Published
- 2013
- Full Text
- View/download PDF
18. ChemInform Abstract: New Glabretal Triterpenes from the Immature Fruits of Poncirus trifoliata and Their Selective Cytotoxicity
- Author
-
In-Kyoung Lee, Hae-Ryong Park, Ae-Ran Choi, Bong-Sik Yun, Jin-Won Kwon, and E. Eum Woo
- Subjects
Terpene ,endocrine system diseases ,Biochemistry ,Chemistry ,Pancreatic cancer ,medicine ,Cytotoxic T cell ,General Medicine ,Stress conditions ,medicine.disease ,Selective cytotoxicity ,digestive system diseases - Abstract
The new title compounds, pancastatins A and B, exhibit selective cytotoxic activity against the PANC-1 pancreatic cancer cells under low-glucose stress conditions.
- Published
- 2016
- Full Text
- View/download PDF
19. Hispidin Analogue Davallialactone Attenuates Carbon Tetrachloride-Induced Hepatotoxicity in Mice
- Author
-
Yeon Jun Jeong, Bong Sik Yun, Baik Hwan Cho, Prabodh Risal, Ho-Keun Yi, Kyu Yun Jang, and Pyoung Han Hwang
- Subjects
Male ,Necrosis ,Pharmaceutical Science ,CCL4 ,Pharmacology ,Analytical Chemistry ,Lactones ,Mice ,chemistry.chemical_compound ,Subcutaneous injection ,Drug Discovery ,medicine ,Animals ,Carbon Tetrachloride ,chemistry.chemical_classification ,Liver injury ,Reactive oxygen species ,Molecular Structure ,Tumor Necrosis Factor-alpha ,Davallialactone ,Organic Chemistry ,Cytochrome P-450 CYP2E1 ,medicine.disease ,Oxidative Stress ,Liver ,Complementary and alternative medicine ,Biochemistry ,chemistry ,Pyrones ,Hepatocytes ,Carbon tetrachloride ,Hispidin ,Molecular Medicine ,Chemical and Drug Induced Liver Injury ,medicine.symptom - Abstract
In this study the protective effects of davallialactone (1), isolated from Inonotus xeranticus, have been examined against carbon tetrachloride (CCl₄-induced acute liver injury. Mice received subcutaneous injection of 1 (2.5, 5, and 10 mg/kg) for three days before CCl₄ injection (1 mg/kg). Protection from liver injury by 1 was confirmed by the observation of decreased serum transaminases and diminished necrosis of liver tissue. Reduced hepatic injury was very similar to that observed with silymarin, a known hepatoprotective drug used in this work for comparison. The groups treated with 1 had reduced reactive oxygen species (ROS), reduced serum malonyldialdehyde levels, and increased levels of liver Cu/Zn superoxide dismutase, as compared to the CCl₄ control group. The expression of heme oxygenase-1 in the liver tissue was increased and the activity of liver cytochrome P4502E1 was restored in the mice treated with 1. In addition, levels of serum tumor necrosis factor-alpha (TNF-α), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2), numbers of macrophage, and cleaved caspase-3-positive hepatocytes were reduced in the groups treated with 1. These findings suggest that davallialactone has protective effects against CCl₄-induced acute liver injury, and this protection is likely due to the suppression of ROS-induced lipid peroxidation and inflammatory response.
- Published
- 2012
- Full Text
- View/download PDF
20. Screening of Antagonistic Bacteria for Biological control of Ginseng Root Rot
- Author
-
In-Kyoung Lee, Bong-Sik Yun, Woon-Hyung Yeo, Ja-Gyeong Song, Ji-Hee Yeom, Myeong-Seok Lee, and Young-Sook Kim
- Subjects
Ecology ,Biochemistry ,Chemistry ,Plant Science ,Ecology, Evolution, Behavior and Systematics - Abstract
인삼의 뿌리썩음병 방제를 위하여 다양한 식물 근권 토양으로부터 유용방선균을 분리하였으며 이들의 생물활성을 조사하였다. 93종의 분리 방선균 중 콜로니가 상이하고 항균활성이 우수한 방선균 8종을 선발하였다. 이들 방선균(A75, A501, A515, A523, A704, A03-1444, A3265, A3283)은 siderophore를 생산하며 cellulase...
- Published
- 2012
- Full Text
- View/download PDF
21. Mechanism of anti-platelet activity ofOligoporus tephroleucusoligoporin A: Involvement of extracellular signal-regulated kinase phosphorylation and cyclic nucleotide elevation
- Author
-
In-Kyoung Lee, Suk Kim, Sang-Keun Kim, Tae-Hwan Kim, Won Jun Oh, Bong-Sik Yun, Gon-Seop Kim, Man Hee Rhee, Jae Youl Cho, Geon-Sik Seo, Hwa-Jin Park, Myung Jin Kim, and Ji Young Park
- Subjects
Blood Platelets ,Male ,Platelet Aggregation ,Platelet Glycoprotein GPIIb-IIIa Complex ,Biology ,Rats, Sprague-Dawley ,Cyclic nucleotide ,chemistry.chemical_compound ,Glucosides ,Cell surface receptor ,Cyclic AMP ,Extracellular ,Animals ,Humans ,Platelet ,Phosphorylation ,Extracellular Signal-Regulated MAP Kinases ,Cyclic GMP ,Kinase ,Fibrinogen ,Fibrinogen binding ,Hematology ,General Medicine ,Platelet Activation ,Triterpenes ,Rats ,Cell biology ,Adenosine Diphosphate ,chemistry ,Biochemistry ,Calcium ,Intracellular ,Signal Transduction - Abstract
This study investigated the inhibitory effects of oligoporin A on platelet aggregation and the mechanism of its action on downstream signaling molecules. Oligoporin A was isolated from the fruiting bodies of Oligoporus tephroleucus (Polyporaceae). The anti-platelet activities of oligoporin A were studied using rat platelets. The effects of oligoporin A on intracellular Ca(2+) mobilization, ATP release, production of the cyclic nucleotides cAMP and cGMP, extracellular signal-regulated kinase (ERK) 2 phosphorylation, and fibrinogen binding to active integrin α(II)(b)β(3) were assessed. Oligoporin A, but not oligoporins B and C, inhibited collagen-induced platelet aggregation in a concentration-dependent manner. Interestingly, oligoporin A did not affect ADP- and thrombin-induced platelet aggregations, which act on different types of membrane receptors. Granule secretion analysis demonstrated that oligoporin A significantly and dose-dependently reduced collagen-induced ATP release and intracellular Ca(2+) mobilization. Additionally, oligoporin A induced the dynamic increase in cAMP and cGMP. Increased cGMP production was further confirmed by the simultaneous production of nitric oxide. Pretreatment with oligoporin A significantly blocked collagen-induced ERK2 phosphorylation. Finally, oligoporin A vaguely diminished the binding of fibrinogen to its cognate receptor, integrin α(II)(b)β(3). The results indicate that oligoporin A inhibits only collagen-induced platelet aggregation mediated through the modulation of downstream signaling molecules. Oligoporin A may be beneficial against cardiovascular disease provoked by aberrant platelet activation.
- Published
- 2012
- Full Text
- View/download PDF
22. Phellinus baumii ethyl acetate extract inhibits lipopolysaccharide-induced iNOS, COX-2, and proinflammatory cytokine expression in RAW264.7 cells
- Author
-
In-Kyoung Lee, Bong-Sik Yun, Seung-Choon Park, Man Hee Rhee, Jae Youl Cho, Taddesse Yayeh, Sang-Keun Kim, Seung-Bok Hong, Tae-Hwan Kim, Won Jun Oh, and Hwa-Jin Park
- Subjects
Lipopolysaccharides ,Lipopolysaccharide ,Blotting, Western ,Interleukin-1beta ,Anti-Inflammatory Agents ,Nitric Oxide Synthase Type II ,Inflammation ,Acetates ,Nitric Oxide ,Dinoprostone ,Gene Expression Regulation, Enzymologic ,Cell Line ,Proinflammatory cytokine ,Nitric oxide ,Immunoenzyme Techniques ,Mice ,chemistry.chemical_compound ,Western blot ,medicine ,Animals ,RNA, Messenger ,Dose-Response Relationship, Drug ,medicine.diagnostic_test ,biology ,Interleukin-6 ,Reverse Transcriptase Polymerase Chain Reaction ,Macrophages ,Granulocyte-Macrophage Colony-Stimulating Factor ,Interleukin ,Molecular biology ,Reverse transcription polymerase chain reaction ,Nitric oxide synthase ,chemistry ,Biochemistry ,Cyclooxygenase 2 ,Solvents ,biology.protein ,Cytokines ,Molecular Medicine ,Medicine, Traditional ,Inflammation Mediators ,medicine.symptom ,Agaricales - Abstract
Mushrooms are valuable sources of biologically active compounds possessing anticancer, antiplatelet, and anti-inflammatory properties. Phellinus baumii is a mushroom used in folk medicine for a variety of human diseases. However, its potential anti-inflammatory effect has remained unclear. Therefore, we studied the effect of P. baumii ethyl acetate extract (PBEAE) on inflammatory mediator and proinflammatory cytokine protein and/or mRNA expression levels using the nitric oxide (NO) assay, enzyme immunoassay (EIA), western blot, and reverse transcription polymerase chain reaction (RT-PCR) in lipopolysaccharide (LPS)-stimulated macrophage like RAW264.7 cells. PBEAE markedly inhibited NO generation and prostaglandin E(2) (PGE(2)) synthesis in a concentration-dependent pattern without any cytotoxic effect at the concentration range used. PBEAE also suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression. In addition, LPS-induced iNOS and COX-2 mRNA expression levels were dose-dependently inhibited by PBEAE pretreatment. Furthermore, PBEAE attenuated the mRNA expression levels of proinflammatory cytokines, specifically interleukin (IL)-1β, IL-6, and granulocyte macrophage colony-stimulating factor (GM-CSF), in a concentration-dependent fashion. Our study suggests that P. baumii might exhibit anti-inflammatory properties by downregulating proinflammatory mediators. Thus, further study on compounds isolated from PBEAE is warranted to investigate the associated molecular mechanisms and identify the potential therapeutic targets.
- Published
- 2011
- Full Text
- View/download PDF
23. Antiatherogenic Effect of Antioxidant Polyphenols from Phellinus baumii in Apolipoprotein E-Deficient Mice
- Author
-
Chul-Ho Lee, Jung Hwan Hwang, In-Kyoung Lee, Yong-Hoon Kim, Jung-Ran Noh, Sun Yung Ly, Bong-Sik Yun, and Gil-Tae Gang
- Subjects
Apolipoprotein E ,medicine.medical_specialty ,Nutrition and Dietetics ,Antioxidant ,Apolipoprotein B ,biology ,Chemistry ,Cholesterol ,Cell adhesion molecule ,medicine.medical_treatment ,Medicine (miscellaneous) ,Interleukin ,Intercellular adhesion molecule ,chemistry.chemical_compound ,Endocrinology ,Biochemistry ,Internal medicine ,Blood plasma ,medicine ,biology.protein - Abstract
Aims: The present study was carried out to investigate the antiatherosclerotic effect of antioxidant polyphenols from Phellinus baumii (PBE) in apolipoprotein E-deficient (apoE–/–) mice. Methods and Results: apoE–/– mice were randomly divided into three groups: mice on a normal chow diet comprised the normal group, mice on an atherogenic diet plus vehicle were the control group, and mice on an atherogenic diet plus PBE (500 mg/kg) comprised the PB500 group. After 8 weeks of treatment, the plasma lipids and cytokine levels were measured. Although no significant differences were found in cholesterol levels among groups, the triglyceride level was significantly decreased in the PBE-treated group compared with the control group. Plasma tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels were reduced by PBE treatment. Real-time PCR analysis of the aorta showed that PBE significantly prevented the upregulation of the vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1, TNF-α, IL-6, and IL-1β expression. Furthermore, reduced macrophage infiltration, lipid accumulation and atherosclerotic lesions were observed in the aortic sinus and en face of the whole aorta in PBE-fed apoE–/– mice compared with atherogenic diet-fed control mice. Conclusions: Collectively, the findings of the present study suggest that the antiatherosclerotic effect of PBE is probably related to the inhibition of adhesion molecule and cytokine expression resulting in amelioration of lesion development.
- Published
- 2011
- Full Text
- View/download PDF
24. Phenylpropanoid acid esters from Korean propolis and their antioxidant activities
- Author
-
Myung-Suk Han, Dae-Won Kim, Bong-Sik Yun, and In-Kyoung Lee
- Subjects
inorganic chemicals ,Antioxidant ,Coumaric Acids ,DPPH ,medicine.medical_treatment ,Clinical Biochemistry ,Pharmaceutical Science ,Phenylpropanoic acid ,Biochemistry ,Antioxidants ,Propolis ,chemistry.chemical_compound ,Republic of Korea ,Drug Discovery ,Caffeic acid ,medicine ,Organic chemistry ,Molecular Biology ,Catechol ,ABTS ,Molecular Structure ,Phenylpropanoid ,Organic Chemistry ,Esters ,chemistry ,Molecular Medicine ,DNA Damage - Abstract
Ten phenylpropanoic acid esters were isolated from an ethanolic extract of Korean propolis. Their structures were elucidated by spectroscopic methods including NMR and ESI-MS. Caffeic acid esters with catechol moiety exhibited significant ABTS and DPPH radical scavenging activity and protective effect against DNA damage by a Fenton reaction.
- Published
- 2014
- Full Text
- View/download PDF
25. Phellinins A1 and A2, new styrylpyrones from the culture broth of Phellinus sp. KACC93057P: I. Fermentation, taxonomy, isolation and biological properties
- Author
-
Nak Beom Jeon, In-Kyoung Lee, Bong-Sik Yun, Geon-Sik Seo, and Hee-Wan Kang
- Subjects
Pharmacology ,Phellinus ,Basidiomycota ,Free Radical Scavengers ,Biology ,Free radical scavenger ,biology.organism_classification ,Styrenes ,chemistry.chemical_compound ,Column chromatography ,chemistry ,Biochemistry ,Pyrones ,Sephadex ,Fermentation ,Drug Discovery ,Hispidin ,Taxonomy (biology) ,Ribosomal DNA ,Chromatography, High Pressure Liquid - Abstract
Novel styrylpyrones, phellinins A1 and A2, were isolated together with known styrylpyrone compounds, hispidin and 1,1-distyrylpyrylethan, from the cultured broth of Phellinus sp. KACC93057P. These compounds were purified by solvent partition, Sephadex LH-20 column chromatography, C(18)-solid phase extraction and finally by reversed-phase (ODS) TLC. To identify the phellinin producer Phellinus sp. KACC93057P, the ribosomal DNA (rDNA) internal transcribed space regions containing 5.8 rDNA were sequenced and compared with those of the known Phellinus isolates. Phellinus sp. KACC93057P was 94.8% identical to P. baumii and P. linteus, all of which did not produce phellinins A1 and A2. These compounds significantly scavenged free radicals such as 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) and superoxide.
- Published
- 2009
- Full Text
- View/download PDF
26. Src kinase-targeted anti-inflammatory activity of davallialactone fromInonotus xeranticusin lipopolysaccharide-activated RAW264.7 cells
- Author
-
Jae Youl Cho, Yong Gyu Lee, In Kyoung Lee, Bong Sik Yun, J Y Kim, Man Hee Rhee, Whi Min Lee, and Jae-Won Lee
- Subjects
Pharmacology ,Kinase ,Davallialactone ,Biology ,Cell biology ,chemistry.chemical_compound ,Biochemistry ,chemistry ,Mitogen-activated protein kinase ,biology.protein ,Hispidin ,Signal transduction ,Kinase activity ,Protein kinase B ,Proto-oncogene tyrosine-protein kinase Src - Abstract
Background and purpose: Mushrooms are popular both as food and as a source of natural compounds of biopharmaceutical interest. Some mushroom-derived compounds such as β-glucan have been shown to be immunostimulatory; this study explores the anti-inflammatory properties of hispidin analogues derived from the mushroom, Inonotus xeranticus. We sought to identify the molecular mechanism of action of these hispidin analogues by determining their effects on lipopolysaccharide (LPS)-mediated inflammatory responses in a macrophage cell line. Experimental approach: The production of inflammatory mediators was determined by Griess assay, reverse transcription-PCR and ELISA. The inhibitory effect of davalliactone on LPS-induced activation of signalling cascades was assessed by western blotting, immunoprecipitation and direct kinase assay. Key results: In activated RAW264.7 cells, davallialactone strongly downregulated LPS-mediated inflammatory responses, including NO production, prostaglandin E2 release, expression of proinflammatory cytokine genes and cell surface expression of co-stimulatory molecules. Davallialactone treatment did not alter cell viability or morphology. Davallialactone was found to exert its anti-inflammatory effects by inhibiting a signalling cascade that activates nuclear factor kappa B via PI3K, Akt and IKK, but not mitogen-activated protein kinases. Treatment with davallialactone affected the phosphorylation of these signalling proteins, but not their level of expression. These inhibitory effects were not due to the interruption of toll-like receptor 4 binding to CD14. In particular, davallialactone strongly inhibited the LPS-induced phosphorylation and kinase activity of Src, implying that Src may be a potential pharmacological target of davallialactone. Conclusions and implications: Our data suggest that davallialactone, a small molecule found in edible mushrooms, has anti-inflammatory activity. Davallialactone can be developed as a pharmaceutically valuable anti-Src kinase agent. British Journal of Pharmacology (2008) 154, 852–863; doi:10.1038/bjp.2008.136; published online 5 May 2008
- Published
- 2008
- Full Text
- View/download PDF
27. Sesquiterpene Furan Compound CJ-01, a Novel Chitin Synthase 2 Inhibitor from Chloranthus japonicus SIEB
- Author
-
Ki Duk Park, Nack Do Sung, Sang-Han Lee, Sung Uk Kim, Jae Sun Moon, Bong Sik Yun, Eui Il Hwang, and Nam Hui Yim
- Subjects
Magnetic Resonance Spectroscopy ,Chloranthus japonicus ,Stereochemistry ,Saccharomyces cerevisiae ,Molecular Conformation ,Pharmaceutical Science ,Microbial Sensitivity Tests ,Sesquiterpene ,chemistry.chemical_compound ,Chitin synthase 2 ,Furan ,Animals ,Humans ,Enzyme Inhibitors ,IC50 ,Chitin Synthase ,Pharmacology ,Membranes ,biology ,fungi ,Fungi ,General Medicine ,Nuclear magnetic resonance spectroscopy ,Chitin synthase ,Plants ,biology.organism_classification ,Mycoses ,chemistry ,Biochemistry ,biology.protein ,Sesquiterpenes - Abstract
A novel sesquiterpene furan compound CJ-01 was isolated from the methanol extract of the whole plant of Chloranthus japonicus SIEB. by monitoring the inhibitory activity of chitin synthase 2 from Saccharomyces cerevisiae. Based on spectroscopic analysis, the structure of compound CJ-01 was determined as 3,4,8a-trimethyl-4a,7,8,8a-tetrahydro-4a-naphto[2,3-b]furan-9-one. The compound inhibited chitin synthase 2 of Saccharomyces cerevisiae in a dose-dependent manner with an IC50 of 39.6 microg/ml, whereas it exhibited no inhibitory activities against chitin synthase 1 and 3 of S. cerevisiae up to 280 microg/ml. CJ-01 has 1.7-fold stronger inhibitory activity than polyoxin D (IC50=70 microg/ml), a well-known chitin synthase inhibitor. These results indicate that the compound is a specific inhibitor of chitin synthase 2 from S. cerevisiae. In addition, CJ-01 showed antifungal activities against various human and phytopathogenic fungi. Therefore, the compound might be an interesting lead to develop effective antifungal agents.
- Published
- 2008
- Full Text
- View/download PDF
28. New antioxidant polyphenols from the medicinal mushroom Inonotus obliquus
- Author
-
Bong-Sik Yun, Young-Sook Kim, Yoon-Woo Jang, Jin-Young Jung, and In-Kyoung Lee
- Subjects
Magnetic Resonance Spectroscopy ,Antioxidant ,Free Radicals ,DPPH ,medicine.medical_treatment ,Clinical Biochemistry ,Pharmaceutical Science ,Pharmacognosy ,Biochemistry ,Antioxidants ,chemistry.chemical_compound ,Phenols ,Drug Discovery ,medicine ,Molecular Biology ,Flavonoids ,Mushroom ,Plants, Medicinal ,ABTS ,Molecular Structure ,biology ,Traditional medicine ,Organic Chemistry ,Polyphenols ,Free radical scavenger ,biology.organism_classification ,chemistry ,Polyphenol ,Molecular Medicine ,Inonotus obliquus ,Agaricales - Abstract
The fruiting body of Inonotus obliquus, a medicinal mushroom called chaga, has been used as a traditional medicine for cancer treatment. Although this mushroom has been known to exhibit potent antioxidant activity, the mechanisms responsible for this activity remain unknown. In our investigation for free radical scavengers from the methanolic extract of this mushroom, inonoblins A (1), B (2), and C (3) were isolated along with the known compounds, phelligridins D (4), E (5), and G (6). Their structures were established by extensive spectroscopic analyses. These compounds exhibited significant scavenging activity against the ABTS radical cation and DPPH radical, and showed moderate activity against the superoxide radical anion.
- Published
- 2007
- Full Text
- View/download PDF
29. Highly oxygenated and unsaturated metabolites providing a diversity of hispidin class antioxidants in the medicinal mushrooms Inonotus and Phellinus
- Author
-
Bong Sik Yun and In-Kyoung Lee
- Subjects
Spectrometry, Mass, Electrospray Ionization ,Magnetic Resonance Spectroscopy ,Phellinus ,Spectrophotometry, Infrared ,Stereochemistry ,DPPH ,Clinical Biochemistry ,Pharmaceutical Science ,Biochemistry ,Antioxidants ,chemistry.chemical_compound ,Picrates ,Superoxides ,Spectroscopy, Fourier Transform Infrared ,Drug Discovery ,Organic chemistry ,Benzothiazoles ,Fruiting Bodies, Fungal ,Molecular Biology ,ABTS ,biology ,Inonotus ,Davallialactone ,Hispolon ,Biphenyl Compounds ,Organic Chemistry ,Free Radical Scavengers ,Hymenochaetaceae ,Oxidants ,biology.organism_classification ,Molecular Weight ,chemistry ,Pyrones ,Hispidin ,Molecular Medicine ,Spectrophotometry, Ultraviolet ,Sulfonic Acids ,Agaricales - Abstract
Three new highly oxygenated and unsaturated metabolites named interfungins A (1), B (2), and C (3), which provide a diversity of hispidin class compounds in the fungi Inonotus and Phellinus, were isolated from the methanolic extract of the fruiting body of the fungus Inonotus xeranticus (Hymenochaetaceae). Their structures were established by spectroscopic methods. The existence of these functionalized metabolites implies that inoscavin A, davallialactone, and phelligridin F, which were previously isolated from the fungi Inonotus and Phellinus spp., are derived from 1. Compound 1 is derived from the condensation of hispidin and hispolon. Inoscavins B and C previously isolated from the fungus I. xeranticus are most probably derived from 2 which stemmed from the oxidative coupling of 3,4-dihydroxybenzalacetone and hispidin. This class of compounds exhibited significant free radical scavenging activity against the superoxide radical cation, ABTS radical anion, and DPPH radical.
- Published
- 2007
- Full Text
- View/download PDF
30. Inhibition of Chitin Synthases and Antifungal Activities by 2'-Benzoyloxycinnamaldehyde from Pleuropterus ciliinervis and Its Derivatives
- Author
-
Byoung Mog Kwon, Bong Sik Yun, Chul Soo Shin, Sung Uk Kim, Tae Hoon Kang, Eui Il Hwang, and Ki Duk Park
- Subjects
Antifungal Agents ,Saccharomyces cerevisiae ,Pharmaceutical Science ,Microbial Sensitivity Tests ,Inhibitory postsynaptic potential ,Benzoates ,Chemical synthesis ,Microbiology ,chemistry.chemical_compound ,Chitin ,Humans ,Acrolein ,Enzyme Inhibitors ,IC50 ,Candida ,Chitin Synthase ,Pharmacology ,Cryptococcus neoformans ,Dose-Response Relationship, Drug ,Molecular Structure ,biology ,Plant Extracts ,fungi ,General Medicine ,Chitin synthase ,Plant Components, Aerial ,Pyrimidine Nucleosides ,biology.organism_classification ,Polygonaceae ,Aminoglycosides ,Biochemistry ,chemistry ,biology.protein ,Pleuropterus - Abstract
In the course of search for potent chitin synthase inhibitors from natural resources, a novel chitin synthases inhibitor, 2'-benzoyloxycinnamaldehyde (2'-BCA) (I), was isolated from the aerial parts of Pleuropterus ciliinervis NAKAI. 2'-BCA inhibited chitin synthase 1 and 2 of Saccharomyces cerevisiae with the IC50s of 54.9 and 70.8 microg/ml, respectively, whereas it exhibited no inhibitory activity for chitin synthase 3 up to 280 microg/ml. Its derivatives, 2'-chloro- (V) and 2(-bromo-cinnamaldehyde (VI), each showed 1.9 and 2.7-fold stronger inhibitory activities than 2'-BCA, with the IC50s of 37.2 and 26.6 microg/ml, respectively. Especially, the IC50 of compound VI against chitin synthase 2 represented 1.7-fold more potent inhibitory activity than polyoxin D, a well-known chitin synthase inhibitor. Furthermore, compounds V and VI showed potent antifungal activities against various fungi including human pathogenic fungi, with a particularly strong inhibitory activity against Cryptococcus neoformans (MIC = 16 microg/ml). Although the chemical synthesis of this compound has been reported, the present study is the first report to describe the isolation of 2'-BCA from natural resources and chitin synthases inhibitory activities of its derivatives. These results suggested that 2'-BCA and its derivatives can potentially serve as useful lead compounds for development of antifungal agents.
- Published
- 2007
- Full Text
- View/download PDF
31. Leinamycin E1 acting as an anticancer prodrug activated by reactive oxygen species
- Author
-
Jianhua Ju, Sheng-Xiong Huang, Bong Sik Yun, Gudrun Ingenhorst, Hirak S. Basu, Ben Shen, Yong Huang, Gong-Li Tang, Dong Yang, Tao Liu, Dawn R. Church, Ming Ma, Jeremy R. Lohman, and George Wilding
- Subjects
Male ,Magnetic Resonance Spectroscopy ,Lactams ,Antineoplastic Agents ,Leinamycin ,chemistry.chemical_compound ,Biosynthesis ,Cell Line, Tumor ,Commentaries ,LNCaP ,Humans ,Prodrugs ,Cell Proliferation ,chemistry.chemical_classification ,Reactive oxygen species ,Multidisciplinary ,Dose-Response Relationship, Drug ,Molecular Structure ,Cell growth ,Prostatic Neoplasms ,Thiones ,Prodrug ,Biological Sciences ,Streptomyces ,DNA Alkylation ,Thiazoles ,chemistry ,Biochemistry ,Cancer cell ,Macrolides ,Reactive Oxygen Species - Abstract
Leinamycin (LNM) is a potent antitumor antibiotic produced by Streptomyces atroolivaceus S-140, featuring an unusual 1,3-dioxo-1,2-dithiolane moiety that is spiro-fused to a thiazole-containing 18-membered lactam ring. Upon reductive activation in the presence of cellular thiols, LNM exerts its antitumor activity by an episulfonium ion-mediated DNA alkylation. Previously, we have cloned the lnm gene cluster from S. atroolivaceus S-140 and characterized the biosynthetic machinery responsible for the 18-membered lactam backbone and the alkyl branch at C3 of LNM. We now report the isolation and characterization of leinamycin E1 (LNM E1) from S. atroolivacues SB3033, a ΔlnmE mutant strain of S. atroolivaceus S-140. Complementary to the reductive activation of LNM by cellular thiols, LNM E1 can be oxidatively activated by cellular reactive oxygen species (ROS) to generate a similar episulfonium ion intermediate, thereby alkylating DNA and leading to eventual cell death. The feasibility of exploiting LNM E1 as an anticancer prodrug activated by ROS was demonstrated in two prostate cancer cell lines, LNCaP and DU-145. Because many cancer cells are under higher cellular oxidative stress with increased levels of ROS than normal cells, these findings support the idea of exploiting ROS as a means to target cancer cells and highlight LNM E1 as a novel lead for the development of anticancer prodrugs activated by ROS. The structure of LNM E1 also reveals critical new insights into LNM biosynthesis, setting the stage to investigate sulfur incorporation, as well as the tailoring steps that convert the nascent hybrid peptide-polyketide biosynthetic intermediate into LNM.
- Published
- 2015
32. Acetyl Eburicoic Acid from Laetiporus sulphureus var. miniatus Suppresses Inflammation in Murine Macrophage RAW 264.7 Cells
- Author
-
Young-Min Son, Bong-Sik Yun, Evelyn Saba, Man Hee Rhee, Seong-Eun Kim, In-Kyoung Lee, and Bo Ra Jeon
- Subjects
chemistry.chemical_classification ,Laetiporus sulphureus var. miniatus ,Acetyl eburicoic acid ,Biological activity ,Nitric oxide ,Biology ,Proinflammatory cytokine ,biology.organism_classification ,Microbiology ,Lanostane ,chemistry.chemical_compound ,Infectious Diseases ,Triterpene ,chemistry ,Biochemistry ,Anti-inflammation ,Laetiporus sulphureus ,Laetiporus ,RAW 264.7 Cells ,Polyporaceae ,Research Article - Abstract
The basidiomycete Laetiporus sulphureus var. miniatus belongs to the Aphyllophorales, Polyporaceae, and grows on the needleleaf tree. The fruiting bodies of Laetiporus species are known to produce N-methylated tyramine derivatives, polysaccharides, and various lanostane triterpenoids. As part of our ongoing effort to discover biologically active compounds from wood-rotting fungi, an anti-inflammatory triterpene, LSM-H7, has been isolated from the fruiting body of L. sulphureus var. miniatus and identified as acetyl eburicoic acid. LSM-H7 dose-dependently inhibited the NO production in RAW 264.7 cells without any cytotoxicity at the tested concentrations. Furthermore it suppressed the production of proinflammatory cytokines, mainly inducible nitric oxide synthase, cyclooxygenase-2, interleukin (IL)-1β, IL-6 and tumor necrosis factor α, when compared with glyceraldehyde 3-phosphate dehydrogenase. These data suggest that LSM-H7 is a crucial component for the anti-inflammatory activity of L. sulphureus var. miniatus.
- Published
- 2015
33. Melanocins A, B and C, New Melanin Synthesis Inhibitors Produced by Eupenicillium shearii: I. Taxonomy, Fermentation, Isolation and Biological Properties
- Author
-
Choong Hwan Lee, Yu-Ryang Pyun, Won Gon Kim, Bong Sik Yun, Byoung Kwon Kim, In Ja Ryoo, Jong Pyung Kim, Ick Dong Yoo, In Kyung Lee, and Sangku Lee
- Subjects
Melanins ,Pharmacology ,Cyanides ,Formamides ,Monophenol Monooxygenase ,Chemistry ,Superoxide ,DPPH ,Free Radical Scavengers ,Butanones ,Streptomyces ,Anti-Bacterial Agents ,Melanin ,chemistry.chemical_compound ,Ascomycota ,Biochemistry ,Drug Discovery ,Eupenicillium ,Fermentation ,Enzyme Inhibitors ,Agaricales ,Eupenicillium shearii ,Streptomyces bikiniensis ,Mycelium - Abstract
New melanin synthesis inhibitors, melanocins A, B and C, were isolated from the fermentation broth and mycelium extract of Eupenicillium shearii F80695. Melanocin A, an isocyanide compound, inhibited mushroom tyrosinase and melanin biosynthesis of B16 melanoma cells with IC50 value of 9.0 nM and MIC value of 0.9 microM, respectively. Melanocin A also inhibited growth of Streptomyces bikiniensis. While, the structurally very related but non-isocyanide compounds melanocins B and C did not show inhibitory activity in these assays. Melanocins A, B and C showed potent antioxidant activity with scavenging activity of DPPH radical and superoxide anion radical.
- Published
- 2003
- Full Text
- View/download PDF
34. [Untitled]
- Author
-
In Ja Ryoo, Ick Dong Yoo, Soo Young Lee, Bong Sik Yun, Sei Kwan Oh, and Myeong Heon Shin
- Subjects
Kainic acid ,Excitotoxicity ,Neurotoxicity ,Kainate receptor ,General Medicine ,AMPA receptor ,Biology ,Pharmacology ,medicine.disease_cause ,medicine.disease ,Biochemistry ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,medicine.anatomical_structure ,nervous system ,chemistry ,medicine ,DNQX ,Cyclothiazide ,Neuron ,medicine.drug - Abstract
Excitatory amino acids are known to induce considerable neurotoxicity in central nervous system. In the present study, the neurotoxicity was induced by application of kainate or AMPA in chick telencephalic neuron, and neuroprotective activity was tested with complestatin that was isolated from streptomyces species. In cultured telencephalic neurons exposed to 500 μM kainate for 2 days, the AMPA/kainate receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX, 5 μM) completely blocked kainate-induced neurotoxicity. Also, complestatin (0.5 μM) completely blocked kainate-induced neuronal injury at a concentration lower than that required for prototype AMPA/kainate receptor antagonist DNQX. In addition, complestatin blocked AMPA-induced neurotoxicity when the neurons were pretreated with cyclothiazide, a desensitization blocker of AMPA receptor. Surprisingly, when the onset of the treatment was delayed for 6 hours, complestatin led to a reduction in kainate-induced neuronal injury. While inhibition of protein kinase C (PKC) by staurosporin induced neurotoxicity, that was blocked by complestatin. Activation of PKC by phorbol dibutyrate partially inhibited the kainate-induced neurotoxicity. These results suggest that complestatin may be used as an anti-excitotoxic agent and involved in the PKC activation contributing to inhibition of neurotoxicity.
- Published
- 2002
- Full Text
- View/download PDF
35. New antioxidant sesquiterpenes from a culture broth of Coprinus echinosporus
- Author
-
Dae-Won Ki, Bong-Sik Yun, Soon-Ja Seok, In-Kyoung Lee, Seung Woong Lee, Byung Soon Hwang, and Dae-Won Kim
- Subjects
Antioxidant ,medicine.medical_treatment ,Radical ,Coprinus ,Butylated Hydroxyanisole ,Oxidative phosphorylation ,Biology ,medicine.disease_cause ,Antioxidants ,chemistry.chemical_compound ,Inhibitory Concentration 50 ,Picrates ,Drug Discovery ,medicine ,Benzothiazoles ,Chromans ,Pharmacology ,chemistry.chemical_classification ,Reactive oxygen species ,Molecular Structure ,Biphenyl Compounds ,biology.organism_classification ,Culture Media ,Biphenyl compound ,chemistry ,Biochemistry ,Butylated hydroxyanisole ,Sulfonic Acids ,Sesquiterpenes ,Oxidative stress - Abstract
Oxidative stress caused by the disproportionate production of reactive oxygen species (free radicals), as compared with the elimination of these products by endogenous antioxidants, is considered to be one of the main causes in the progression of rheumatoid arthritis, arteriosclerosis, ischemic stroke, autoimmune disease, diabetes, cancer initiation and aging.1, 2, 3, 4, 5 Thus, an intake of natural antioxidants has been posited to reduce the risk of developing some of these pathologies related to oxidative stress.6 During a search for natural antioxidants from fungal strains, we found that the culture broth of Coprinus echinosporus exhibited potent free radical scavenging activity. C. echinosporus is a basidiomycete belonging to the genus Coprinus together with C. comatus, C. cinereus, C. plicatilis and C. radians. The genus Coprinus was reported to produce diverse sesquiterpenes, diterpenoids, triterpenoids and piperidine derivatives, which were reported to exhibit anti-inflammatory, antioxidant, anti-cancer, anti-bacterial, anti-fungal and cerebral blood flow-improving effects.7, 8, 9, 10, 11, 12 In this study, we report the isolation and structure determination of novel sesquiterpenes (2–4, Figure 1) and their antioxidant properties.
- Published
- 2014
36. Absolute stereochemistry and solution conformation of promothiocins
- Author
-
Haruo Seto, Bong Sik Yun, Ken-ichi Fujita, and Kazuo Furihata
- Subjects
biology ,Molecular model ,Stereochemistry ,Organic Chemistry ,Biological activity ,biology.organism_classification ,Biochemistry ,Streptomyces ,chemistry.chemical_compound ,chemistry ,Valine ,Dehydroalanine ,Drug Discovery ,Side chain - Abstract
Two members of thiopeptide class antibiotics, promothiocins A and B, were previously isolated from the mycelial extract of Streptomyces sp. SF2741 as tipA promoter inducing substances. Promothiocins are unique 26-membered thiopeptides composed of valine, 2-aminomethyl-5-methyloxazole-4-carboxylic acid, 2-(1-aminoethyl)thiazole-4-carboxylic acid, 2-(2-(1-aminoethyl)-5-methyloxazolyl)-3-(4-carboxythiazolyl)pyridine-6-carboxylic acid and dehydroalanine(s). The absolute stereochemistry and solution conformation of promothiocins have been investigated by a combination of the degradation works and molecular modeling experiments. These compounds contain characteristic dehydroalanine side chains in their structures that are closely related to promoter inducing activity, but are not essential.
- Published
- 2001
- Full Text
- View/download PDF
37. Ellagic acid rhamnosides from the stem bark of Eucalyptus globulus
- Author
-
Bong Sik Yun, In Kyoung Lee, Hiroyuki Koshino, Sung Hyun Chung, Ick Dong Yoo, Jong Pyung Kim, and Gyu Seop Shim
- Subjects
Antioxidant ,Stereochemistry ,medicine.medical_treatment ,Plant Science ,Horticulture ,Biology ,Pharmacognosy ,Rhamnose ,Biochemistry ,Antioxidants ,Lipid peroxidation ,Biological Factors ,Inhibitory Concentration 50 ,chemistry.chemical_compound ,Ellagic Acid ,medicine ,Animals ,Molecular Biology ,chemistry.chemical_classification ,Eucalyptus ,Plants, Medicinal ,Chromatography ,Plant Stems ,Plant Extracts ,Glycoside ,General Medicine ,Carbon-13 NMR ,biology.organism_classification ,Rats ,chemistry ,visual_art ,Eucalyptus globulus ,Microsomes, Liver ,visual_art.visual_art_medium ,Bark ,Lipid Peroxidation ,Ellagic acid - Abstract
Four ellagic acid rhamnosides were isolated from the stem bark of Eucalyptus globulus. Their structures have been established on the basis of the analysis of their 1H NMR, 13C NMR, HMBC, IR and MS spectral data. The HMBC data of these compounds were most useful for their structure determinations, with these bring determined to be 3-O-methylellagic acid 3'-O-alpha-rhamnopyranoside, 3-O-methylellagic acid 3'-O-alpha-3''-O-acetylrhamnopyranoside, 3-O-methylellagic acid 3'-O-alpha-2''-O-acetylrhamnopyranoside, 3-O-methylellagic acid 3'-O-alpha-4''-O-acetylrhamnopyranoside, respectively. Their antioxidant activities were evaluated by measuring the inhibition of lipid peroxidation using rat liver microsomes, with IC50 values of 10.0-14.0 microg/ml.
- Published
- 2001
- Full Text
- View/download PDF
38. Thiopeptide Non-producing Streptomyces Species Carry the tipA Gene: A Clue to Its Function
- Author
-
Tomomi Hidaka, Bong Sik Yun, Tomohisa Kuzuyama, and Haruo Seto
- Subjects
DNA, Bacterial ,Pharmacology ,Genetics ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,Streptomycetaceae ,Molecular cloning ,biology.organism_classification ,Streptomyces ,Streptomyces species ,Anti-Bacterial Agents ,Blotting, Southern ,Bacterial Proteins ,Biochemistry ,Drug Discovery ,Trans-Activators ,Thioxamycin ,Actinomycetales ,Peptides ,Promoter Regions, Genetic ,Gene ,Function (biology) - Published
- 2001
- Full Text
- View/download PDF
39. Neuroprotectins A and B, Bicyclohexapeptides Protecting Chick Telencephalic Neuronal Cells from Excitotoxicity. I. Fermentation, Isolation, Physico-chemical Properties and Biological Activity
- Author
-
Kenichi Suzuki, Bong Sik Yun, Jung Sik Kim, In Ja Ryoo, Chang-Jin Kim, Ick Dong Yoo, Hiroyuki Kobayashi, Haruo Seto, Koji Nagai, Kazuo Shin-ya, and Yoichi Hayakawa
- Subjects
Kainic acid ,Excitotoxicity ,Nerve Tissue Proteins ,Chick Embryo ,Biology ,medicine.disease_cause ,Receptors, N-Methyl-D-Aspartate ,Neuroprotection ,chemistry.chemical_compound ,Drug Discovery ,medicine ,Animals ,Neurotoxin ,Cells, Cultured ,Pharmacology ,chemistry.chemical_classification ,Membrane Glycoproteins ,Neurotoxicity ,Glutamate receptor ,Glutamic acid ,medicine.disease ,Amino acid ,Neuroprotective Agents ,chemistry ,Biochemistry ,Fermentation ,Oligopeptides - Abstract
Glutamate, an excitatory amino acid, is known to induce neurotoxicity in central nervous system under abnormal conditions such as ischemia, hypoglycemia, epilepsy, Huntington's chorea, Parkinson's disease and Alzheimer's disease. In our search for neuroprotective agents of microbial origin against excitatory neurotoxins, we have isolated two new bicyclohexapeptides, neuroprotectins A and B, together with a known compound complestatin, from the fermentation broth of Streptomyces sp. Q27107. Neuroprotectins protected primary cultured chick telencephalic neurons from glutamate- and kainate-induced excitotoxicities in a dose-dependant fashion.
- Published
- 2001
- Full Text
- View/download PDF
40. Styrylpyrones from the medicinal fungus Phellinus baumii and their antioxidant properties
- Author
-
Bong-Sik Yun, Young-Sook Kim, Myeong-Seok Lee, Myung-Suk Han, and In-Kyoung Lee
- Subjects
Antioxidant ,Iron ,medicine.medical_treatment ,Clinical Biochemistry ,Pharmaceutical Science ,Fungus ,Pharmacognosy ,Iron Chelating Agents ,Hypholomine B ,Biochemistry ,Antioxidants ,chemistry.chemical_compound ,Drug Discovery ,medicine ,Medicinal fungi ,DNA Breaks, Single-Stranded ,Molecular Biology ,biology ,Traditional medicine ,Basidiomycota ,Davallialactone ,Organic Chemistry ,DNA ,biology.organism_classification ,chemistry ,Pyrones ,Hispidin ,Molecular Medicine - Abstract
During the search for natural antioxidants from basidiomycetes, a new styrylpyrone, baumin (1), was isolated from the cultivated medicinal fungus Phellinus baumii, together with known compounds, davallialactone (2), hispidin (3), hypholomine B (4), interfungin A (5), inoscavin A (6), and phelligridin D (7), which were previously isolated from the medicinal fungi Phellinusignarius, Phellinuslinteus, and Inonotus xeranticus. Their structures were elucidated by extensive spectroscopic methods. These compounds exhibited antioxidant activity through Fenton reaction inhibition via iron chelation and free radical scavenging.
- Published
- 2010
- Full Text
- View/download PDF
41. Chaetoatrosin A, a Novel Chitin Synthase II Inhibitor Produced by Chaetomium atrobrunneum F449
- Author
-
Bong Sik Yun, Kyung Sook Bae, Sung Uk Kim, Eui Il Hwang, Young-Kook Kim, Hong Gi Kim, Hyang Bok Lee, and Byoung-Mog Kwon
- Subjects
Chitin Synthase ,Pharmacology ,Cryptococcus neoformans ,Antifungal Agents ,Chromatography ,biology ,Fungi ,Chaetomium atrobrunneum ,Naphthols ,Chitin synthase ,Chaetomium ,biology.organism_classification ,Mass Spectrometry ,Enzyme assay ,Rhizoctonia solani ,Mycoses ,Biochemistry ,Sephadex ,Fermentation ,Drug Discovery ,biology.protein ,Humans ,Enzyme Inhibitors ,Botrytis cinerea - Abstract
Chaetoatrosin A, a novel chitin synthase II inhibitor, was isolated from the culture broth of fungus F449, which was identified as Chaetomium atrobrunneum F449. Chaetoatrosin A was purified by solvent partition, silica gel, ODS, preparative TLC, and Sephadex LH-20 column chromatographies, consecutively. The structure of chaetoatrosin A was assigned as 1,8-dihydroxy-3(2-hydroxypropionyl)-6-methoxynaphthalene on the basis of various spectroscopic analyses including UV, IR, mass spectral, and NMR. Its molecular weight and formula were found to be 262 and C 14 H 14 O 5 , respectively. Chaetoatrosin A inhibited chitin synthase II by 50% at the concentration of 104 μg/ml in an enzyme assay system. This compound showed antifungal activities against Rhizoctonia solani, Pyricularia oryzae, Botrytis cinerea. Cryptococcus neoformans and Trichophyton mentagrophytes.
- Published
- 2000
- Full Text
- View/download PDF
42. Phellinsin A, a Novel Chitin Synthases Inhibitor Produced by Phellinus sp. PL3
- Author
-
Won Jin Jeong, Young Kook Kim, Sung Uk Kim, Byoung Mog Kwon, Bong Sik Yun, Hong Gi Kim, Hyang Bok Lee, and Eui Il Hwang
- Subjects
Pyricularia ,Antifungal Agents ,Phellinus ,Microbial Sensitivity Tests ,Aspergillus fumigatus ,Rhizoctonia solani ,Lactones ,chemistry.chemical_compound ,Phenols ,Chitin ,Drug Discovery ,Humans ,Enzyme Inhibitors ,Candida ,Plant Diseases ,Chitin Synthase ,Pharmacology ,chemistry.chemical_classification ,biology ,Basidiomycota ,fungi ,Alternaria ,food and beverages ,Biological activity ,Chitin synthase ,biology.organism_classification ,Enzyme ,chemistry ,Biochemistry ,biology.protein - Abstract
Phellinsin A, a novel chitin synthases inhibitor was isolated from the cultured broth of fungus PL3, which was identified as Phellinus sp. PL3. Phellinsin A was purified by solvent partition, silica gel, ODS column chromatographies, and preparative HPLC, consecutively. The structure of phellinsin A was assigned as a phenolic compound on the basis of various spectroscopic analyses including UV, IR, Mass, and NMR. Its molecular weight and formula were found to be 358 and C18H14O8, respectively. Phellinsin A selectively inhibited chitin synthase I and II of Saccharomyces cerevisiae with an IC50 value of 76 and 28 microg/ml, respectively, in our cell free assay system. This compound showed antifungal activity against Colletotrichum lagenarium, Pyricularia oryzae, Rhizoctonia solani, Aspergillus fumigatus, and Trichophyton mentagrophytes.
- Published
- 2000
- Full Text
- View/download PDF
43. Isolation and sequence analysis of new peptaibol, boletusin, fromBoletus spp
- Author
-
Woon Hyung Yeo, Bong Sik Yun, Ick Dong Yoo, and Sang Jun Lee
- Subjects
Pharmacology ,chemistry.chemical_classification ,Mushroom ,Sequence analysis ,Organic Chemistry ,Peptaibol ,Boletus ,Peptide ,Phenylalanine ,General Medicine ,Biology ,biology.organism_classification ,Biochemistry ,Amino acid ,chemistry.chemical_compound ,Residue (chemistry) ,chemistry ,Structural Biology ,Drug Discovery ,Molecular Medicine ,Molecular Biology - Abstract
A new peptaibol, boletusin, was isolated from the methanol extract of the fruiting body of the mushroom, Boletus spp. Sequential determination by positive FAB MS/MS showed that boletusin is a peptide consisting of 19 amino acids, with one acetylated N-terminus residue, phenylalanine, and a C-terminal amino alcohol, tryptophanol. This peptide showed antimicrobial activity against several Gram-positive bacteria.
- Published
- 1999
- Full Text
- View/download PDF
44. Broad Spectrum Thiopeptide Recognition Specificity of theStreptomyces lividans TipAL Protein and Its Role in Regulating Gene Expression
- Author
-
Anna Maria Puglia, Takaaki Katoh, Mark L. Chiu, Haruo Seto, Charles J. Thompson, Marc Folcher, Bong-Sik Yun, and Jiri Vohradsky
- Subjects
Protein Conformation ,Molecular Sequence Data ,Mutant ,Biology ,Biochemistry ,Streptomyces ,Mass Spectrometry ,Thiostrepton ,chemistry.chemical_compound ,Protein structure ,Bacterial Proteins ,Dehydroalanine ,Amino Acid Sequence ,Molecular Biology ,Regulation of gene expression ,Alanine ,Protein primary structure ,Gene Expression Regulation, Bacterial ,Cell Biology ,biology.organism_classification ,Anti-Bacterial Agents ,chemistry ,Trans-Activators ,Peptides ,Nosiheptide - Abstract
Microbial metabolites isolated in screening programs for their ability to activate transcription of the tipA promoter (ptipA) in Streptomyces lividans define a class of cyclic thiopeptide antibiotics having dehydroalanine side chains ("tails"). Here we show that such compounds of heterogeneous primary structure (representatives tested: thiostrepton, nosiheptide, berninamycin, promothiocin) are all recognized by TipAS and TipAL, two in-frame translation products of the tipA gene. The N-terminal helix-turn-helix DNA binding motif of TipAL is homologous to the MerR family of transcriptional activators, while the C terminus forms a novel ligand-binding domain. ptipA inducers formed irreversible complexes in vitro and in vivo (presumably covalent) with TipAS by reacting with the second of the two C-terminal cysteine residues. Promothiocin and thiostrepton derivatives in which the dehydroalanine side chains were removed lost the ability to modify TipAS. They were able to induce expression of ptipA as well as the tipA gene, although with reduced activity. Thus, TipA required the thiopeptide ring structure for recognition, while the tail served either as a dispensable part of the recognition domain and/or locked thiopeptides onto TipA proteins, thus leading to an irreversible transcriptional activation. Construction and analysis of a disruption mutant showed that tipA was autogenously regulated and conferred thiopeptide resistance. Thiostrepton induced the synthesis of other proteins, some of which did not require tipA.
- Published
- 1999
- Full Text
- View/download PDF
45. Tylopeptins A and B, New Antibiotic Peptides from Tylopilus neofelleus
- Author
-
Bong Sik Yun, Sang Jun Lee, Ick Dong Yoo, and Duck Hyun Cho
- Subjects
Pharmacology ,chemistry.chemical_classification ,Magnetic Resonance Spectroscopy ,biology ,Chemistry ,Stereochemistry ,Gram-positive bacteria ,Molecular Sequence Data ,Peptaibol ,Peptide ,biology.organism_classification ,Anti-Bacterial Agents ,Amino acid ,Residue (chemistry) ,chemistry.chemical_compound ,Biochemistry ,Drug Discovery ,Amino Acid Sequence ,Amino Acids ,Agaricales ,Peptides ,Peptide sequence ,Bacteria ,Peptaibols ,Antibacterial agent - Abstract
Two new peptides, tylopeptins A and B, were isolated from the methanol extract of the fruiting body of the mushroom, Tylopilus neofelleus. These peptides were identified as peptaibols possessing an acetylated N-terminal residue, fourteen amino acids, and leucinol as the C-terminal amino alcohol. Sequential determination and complete 1H and 13C resonance assignments were based on positive ion FAB mass spectroscopy and two dimensional NMR techniques. These peptides were subsequently shown to be active against some gram-positive bacteria, but inactive against pathogenic fungi and gram-negative bacteria.
- Published
- 1999
- Full Text
- View/download PDF
46. Three naphthalenes from root bark of Hibiscus syriacus
- Author
-
In Ja Ryoo, Dong Ho Choung, Kyou-Hoon Han, In Kyung Lee, Bong Sik Yun, and Ick Dong Yoo
- Subjects
Antioxidant ,medicine.medical_treatment ,Chemical structure ,Plant Science ,Naphthalenes ,Spectrometry, Mass, Fast Atom Bombardment ,Horticulture ,Pharmacognosy ,Plant Roots ,Biochemistry ,Antioxidants ,Lipid peroxidation ,chemistry.chemical_compound ,Botany ,medicine ,Animals ,Humans ,Hibiscus syriacus ,Nuclear Magnetic Resonance, Biomolecular ,Molecular Biology ,Malvaceae ,Plants, Medicinal ,biology ,Traditional medicine ,Plant Extracts ,Biological activity ,General Medicine ,biology.organism_classification ,Rats ,Liver ,chemistry ,visual_art ,visual_art.visual_art_medium ,Bark ,Lipid Peroxidation - Abstract
Three new naphthalenes, designated as syriacusins A-C, were isolated from the root bark of Hibiscus syriacus. These compounds were identified as 2,7-dihydroxy-6-methyl-8-methoxy-1-naphthalenecarbaldehyde, 2-hydroxy-6-hydroxymethyl-7,8-dimethoxy-1-naphthalenecarbaldehyde, 1-carboxy-2,8-dihydroxy-6-methyl-7-methoxynaphthalenecarbolactone (1-->8), respectively, on the basis of various spectral studies. The compounds inhibited lipid peroxidation with IC50s of 0.54, 5.90 and 1.02 micrograms ml-1, respectively. The first compound also showed cytotoxicity against some human cancer cell lines with an ED50 of 1.5-2.4 micrograms ml-1.
- Published
- 1998
- Full Text
- View/download PDF
47. Hibispeptin A, a novel cyclic peptide from Hibiscus syriacus
- Author
-
Bong-Sik Yun, In-Ja Ryoo, In-Kyoung Lee, and Ick-Dong Yoo
- Subjects
Organic Chemistry ,Drug Discovery ,Biochemistry - Published
- 1998
- Full Text
- View/download PDF
48. Two novel furan derivatives from Phellinus linteus with anti-complement activity
- Author
-
Bong-Sik Yun, Hyun-Ah Jung, Byung Sun Min, Hee-Jin Jung, Jae Sue Choi, and Hyeong-Kyu Lee
- Subjects
Magnetic Resonance Spectroscopy ,Stereochemistry ,Clinical Biochemistry ,Pharmaceutical Science ,Pharmacognosy ,Biochemistry ,chemistry.chemical_compound ,Furan ,Drug Discovery ,Ic50 values ,medicine ,Humans ,Furans ,Cytotoxicity ,Complement Activation ,Molecular Biology ,Molecular Structure ,biology ,Chemistry ,Basidiomycota ,Organic Chemistry ,Biological activity ,General Medicine ,Complement System Proteins ,biology.organism_classification ,medicine.disease ,In vitro ,Hemolysis ,Complement system ,Phellinus linteus ,Anti complement ,Molecular Medicine - Abstract
Two novel stereoisomers of furan derivatives, phellinusfurans A (1) and B (2), were isolated from the fruiting body of Phellinus linteus. Their structures were elucidated by spectroscopic analysis. Compounds 1 and 2 exhibited significant anti-complement activity with IC50 values of 33.6 and 33.7 microM, respectively, in inhibiting the hemolytic activity of human serum against erythrocytes.
- Published
- 2006
- Full Text
- View/download PDF
49. Davallialactone reduces inflammation and repairs dentinogenesis on glucose oxidase-induced stress in dental pulp cells
- Author
-
Mi-Kyung Yu, Usha Paudel, Bong-Sik Yun, Go-Eun Kim, Nan-Hee Lee, Ho-Keun Yi, Young Hee Lee, and Yong-Beom Song
- Subjects
Antioxidant ,Materials science ,Cell Survival ,medicine.medical_treatment ,Anti-Inflammatory Agents ,Pharmacology ,medicine.disease_cause ,Antioxidants ,chemistry.chemical_compound ,Glucose Oxidase ,Lactones ,stomatognathic system ,medicine ,Diabetes Mellitus ,Humans ,Glucose oxidase ,Angiogenic Proteins ,General Dentistry ,Cells, Cultured ,Dental Pulp ,chemistry.chemical_classification ,Reactive oxygen species ,biology ,Plant Extracts ,Davallialactone ,Pulpitis ,Hydrogen Peroxide ,Dentinogenesis ,Alkaline Phosphatase ,stomatognathic diseases ,Oxidative Stress ,Glucose ,chemistry ,Biochemistry ,Dentin ,biology.protein ,Pulp (tooth) ,Cytokines ,Dentin mineralization ,Inflammation Mediators ,Agaricales ,Reactive Oxygen Species ,Oxidative stress ,Tooth Calcification - Abstract
Introduction The chronic nature of diabetes mellitus (DM) raises the risk of oral complication diseases. In general, DM causes oxidative stress to organs. This study aimed to evaluate the cellular change of dental pulp cells against glucose oxidative stress by glucose oxidase with a high glucose state. The purpose of this study was to test the antioxidant character of davallialactone and to reduce the pathogenesis of dental pulp cells against glucose oxidative stress. Methods The glucose oxidase with a high glucose concentration was tested for hydroxy peroxide (H 2 O 2 ) production, cellular toxicity, reactive oxygen species (ROS) formation, induction of inflammatory molecules and disturbance of dentin mineralization in human dental pulp cells. The anti-oxidant effect of Davallilactone was investigated to restore dental pulp cells' vitality and dentin mineralization via reduction of H 2 O 2 production, cellular toxicity, ROS formation and inflammatory molecules. Results The treatment of glucose oxidase with a high glucose concentration increased H 2 O 2 production, cellular toxicity, and inflammatory molecules and disturbed dentin mineralization by reducing pulp cell activity. However, davallialactone reduced H 2 O 2 production, cellular toxicity, ROS formation, inflammatory molecules, and dentin mineralization disturbances even with a long-term glucose oxidative stress state. Conclusions The results of this study imply that the development of oral complications is related to the irreversible damage of dental pulp cells by DM-induced oxidative stress. Davallialactone, a natural antioxidant, may be useful to treat complicated oral disease, representing an improvement for pulp vital therapy.
- Published
- 2013
50. Thiobutacin, a Novel Antifungal and Antioomycete Antibiotic from Lechevalieria aerocolonigenes
- Author
-
Surk-Sik Moon, Bong Sik Yun, Ick Dong Yoo, Jung Yeop Lee, and Byung Kook Hwang
- Subjects
Phytophthora ,Antifungal Agents ,Carboxylic acid ,Saccharomyces cerevisiae ,Pharmaceutical Science ,Microbial Sensitivity Tests ,Analytical Chemistry ,Actinobacteria ,Actinomycetales ,Candida albicans ,Drug Discovery ,Nuclear Magnetic Resonance, Biomolecular ,Botrytis cinerea ,Pharmacology ,chemistry.chemical_classification ,Korea ,Molecular Structure ,biology ,Organic Chemistry ,Fungi imperfecti ,biology.organism_classification ,Yeast ,Butyrates ,Phytophthora capsici ,Complementary and alternative medicine ,Biochemistry ,chemistry ,Molecular Medicine ,Botrytis ,Bacteria - Abstract
A novel butanoic acid, thiobutacin (1), 4-(2-aminophenyl)-4-oxo-2-methylthiobutanoic acid (C11H13NO3S), was isolated from the culture broth of a soil actinomycete, Lechevalieria aerocolonigenes strain VK-A9. The structure of thiobutacin (1) was elucidated on the basis of the extensive 2D NMR spectral data including 1H-1H COSY, HMBC, HMQC, ROESY, and NOESY. Thiobutacin (1) showed antioomycete and antifungal activity against phytopathogenic Phytophthora capsici and Botrytis cinerea and the yeast Saccharomyces cerevisiae.
- Published
- 2004
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.