A5046649612- Chemical Synthesis and Analysis
- Asymmetric Synthesis and Catalysis
- Cancer, Hypoxia, and Metabolism
- Carbohydrate Chemistry and Synthesis
- Angiogenesis and VEGF in Cancer
- Cytokine Signaling Pathways and Interactions
- Asymmetric Hydrogenation and Catalysis
- Synthesis and Catalytic Reactions
- Bioactive Compounds and Antitumor Agents
- Synthesis and biological activity
- Chemical Synthesis and Reactions
- Photochromic and Fluorescence Chemistry
- Fluorine in Organic Chemistry
- Synthetic Organic Chemistry Methods
- Cancer therapeutics and mechanisms
- Organic Chemistry Cycloaddition Reactions
- Microwave-Assisted Synthesis and Applications
- S100 Proteins and Annexins
- Free Radicals and Antioxidants
- Sulfur-Based Synthesis Techniques
- Inflammatory Bowel Disease
- Melanoma and MAPK Pathways
- Oxidative Organic Chemistry Reactions
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Natural product bioactivities and synthesis
Yeungnam University
2016-2025
Rutgers Cancer Institute of New Jersey
2009-2018
Rutgers, The State University of New Jersey
2009-2018
Yeungnam University College
2018
Government of the Republic of Korea
2018
Vanderbilt University
2010-2013
Seoul National University
2002-2011
Johnson University
2011
Korea Research Institute of Bioscience and Biotechnology
2011
Queen's University
2010
Various N-benzylcinchonidinium salts were prepared to study electronic factors in the catalytic enantioselective phase-transfer alkylation of glycine anion equivalent. An ortho-fluoro substituent on benzyl group quaternary ammonium salt dramatically increased enantioselectivity alkylation. O(9)-Allyl-N-2',3',4'-trifluorobenzylhydrocinchonidinium bromide (27), which gave highest catalysts studied, was used prepare 12 α-alkylated amino acid derivatives 94∼>99% ee.
Bovine embryonic stem (ES) cell lines reported to date vary in morphology and marker expression (e.g., alkaline phosphatase [ALPL], stage-specific antigen 4 [SSEA4], OCT4) that normally are associated with the undifferentiated, pluripotent state. These observations suggest proper experimental conditions for consistently producing bovine ES cells have not been identified. Here, we report three lines, one from vitro-fertilized two nuclear transfer embryos. grew large, multicellular colonies...
A dimeric Cinchona alkaloid ammonium salt, α,α′-bis[O(9)-allylcinchonidinium]-m-x ylene dibromide 4, has been developed as a new efficient phase-transfer catalyst; the catalytic enantioselective alkylation of N-(diphenylmethylene)glycine tert-butyl ester using 4 provided 7 in high enantiomeric excess (90–99% ee).
Dramatic increases in reaction rates and enantioselectivities can be effected by the use of surfactants for phase-transfer catalytic epoxidation aromatic enones. Based on X-ray crystal structure most effective catalyst—a modified cinchona alkaloid—a plausible transition state has been modeled (see picture; HOO− yellow, C gray, H white, N blue, O red). Supporting information this article is available WWW under http://www.wiley-vch.de/contents/jc_2002/2005/z462254_s.pdf or from author. Please...
Human populations contain a functional coding polymorphism (codon 72) in the p53 gene. To explore whether this alters transcriptional pattern of p53-regulated genes, human isogenic cell lines harboring with either proline or arginine at codon 72 were employed to activate p53-mediated transcription. Thirty-four genes assayed for their increased levels mRNA using quantitative real-time PCR. The largest difference between p53-arginine and p53-proline was found PERP gene involved cell-cell...
Abstract Triple-negative breast cancer (TNBC) is a highly metastatic with poor prognosis. In the present study, we demonstrated that Src, non-receptor tyrosine kinase, might provide an effective therapeutic strategy to overcome TNBC invasion and metastasis, which are mediated via synergistic action of lysosomal enzyme cathepsin S (CTSS) gelatinase MMP-9. Knock-down MMP-9 CTSS using siRNAs resulted in suppression MDA-MB-231 cell invasion, was similarly observed pharmacological inhibitors....
Our research group demonstrated that riluzole, an inhibitor of glutamatergic signaling reduced melanoma cell proliferation in vitro and tumor progression vivo. The underlying mechanisms riluzole are largely unknown. Microarray analyses on two human lines revealed stimulates expression the cystine-glutamate amino acid antiporter, xCT (SLC7A11). Western immunoblot analysis from cultured or normal melanocytic cells showed was significantly overexpressed most melanomas, but not cells. Studies...
Abstract An efficient 11‐step synthesis of (±)‐dechlorotrichotoxin A, a dechlorinated analog the cytotoxic marine natural product trichotoxin has been developed. The synthesis, featuring key steps such as cross‐metathesis, Grignard reaction, and Tebbe olefination, encountered significant challenges. These arose from volatility instability intermediates, well difficulty selective introduction functional groups. issues were overcome through strategic protecting group manipulations careful...
Oocyte maturation is a key issue of current animal biotechnology. This study was designed to examine the morphodynamics cumulus-oocyte association during oocyte maturation. Porcine complexes were recovered from slaughterhouse ovaries; matured in vitro for 0, 24, 36, and 44 h; evaluated by scanning electron microscopy either combined or not with osmium-dimethyl sulfoxide-osmium maceration (ODO) method. The cytoskeleton distribution also observed fluorescence staining. Prior culture (0 h),...
A facile synthesis of chiral α-alkyl serines 3 involves the asymmetric alkylation substrates 1 with alkyl halides (RX) under phase-transfer catalysis (PTC), followed by acidic hydrolysis products 2. The phenyl oxazoline moiety enhances acidity α proton ester and is an excellent protecting group for both amino hydroxy functions serine ester. Supporting information this article available on WWW http://www.wiley-vch.de/contents/jc_2002/2004/z53496_s.pdf or from author. Please note: publisher...
The Cinchona alkaloid-derived quaternary ammonium salts containing 2'-N-oxypyridine and 2'-cyanobenzene moieties were prepared evaluated as phase-transfer catalysts in the enantioselective alkylation of glycine imine ester 1. N-oxypyridine cyanobenzene might play an important role to form a rigid conformation by coordinating with H2O via hydrogen bonding leading high enantioselectivity (97∼>99% ee), which provides evidence electronic factor for catalytic efficiency alkylation.
Abstract Glutamate-triggered signal transduction is thought to contribute widely cancer pathogenesis. In melanoma, overexpression of the metabotropic glutamate receptor (GRM)-1 occurs frequently and its ectopic expression in melanocytes sufficient for neoplastic transformation. Clinical evaluation GRM1 signaling inhibitor riluzole patients with advanced melanoma has demonstrated tumor regressions that are associated a suppression mitogen-activated protein kinase (MAPK) phosphoinositide...
Summary Studies demonstrate that GRM , expressed by >60% of human melanomas, may be a therapeutic target. We performed phase II trial 100 mg PO bid riluzole, an inhibitor 1 signaling, in patients with advanced melanoma the primary endpoint response rate. Thirteen 1‐positive tumors were enrolled. No objective responses observed, and accrual was stopped. Stable disease noted six (46%) patients, one patient on study for 42 weeks. Riluzole well tolerated, fatigue (62%) as most common adverse...
CD4+ T cells are the central for mammalian adaptive immune system. Naïve mainly differentiate in to pro-inflammatory Th1, Th2 and Th17 upon antigenic stimulation. IFN-γ secreting Th1 IL-17 found play key roles autoimmune diseases like multiple sclerosis (MS) ulcerative colitis (UC). In this study we NTG-A-009, 6-aminopyridin-3-ol, has great inhibitory effect on vitro differentiation of without affecting regulatory cells. Moreover, NTG-A-009 had no cell proliferation viability. vivo treatment...
The Maillard reaction, known as the condensation of reduced sugars with amino acids, can be a great source pyrroles for discovery bioactive compounds. In present study, using glucose and l-alanine, two new pyrrolopyrazinones (1a 1b) were obtained. Subsequently, more (2a 2b) prepared by further hydrolyzing methyl ester into carboxylic acid. structures determined interpretation 1D 2D NMR HRESIMS data well computational calculation ECD Cotton effects. Moreover, broad 1H peak shapes observed in...
Systematic investigations to develop an efficient enantioselective synthetic method for alpha-alkyl-alanine by catalytic phase-transfer alkylation were performed. The of 2-naphthyl aldimine tert-butyl ester, 1E, with RbOH and O(9)-allyl-N-2',3',4'-trifluorobenzylhydrocinchonidinium bromide, 6, at -35 degrees C showed the highest enantioselectivities, up 96% ee.
An enantioselective synthetic method for (−)-cis-clavicipitic acid (1) was reported. 1 obtained in 10 steps (99% ee and 20% overall yield) from 1H-indole-3-carboxylic methyl ester (9) via asymmetric phase-transfer catalytic alkylation diastereoselective Pd(II)-catalyzed intramolecular aminocyclization as key steps.