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Li W, Yu B. Temporary ether protecting groups at the anomeric center in complex carbohydrate synthesis. Adv Carbohydr Chem Biochem 2020; 77:1-69. [PMID: 33004110 DOI: 10.1016/bs.accb.2019.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The synthesis of a carbohydrate building block usually starts with introduction of a temporary protecting group at the anomeric center and ends with its selective cleavage for further transformation. Thus, the choice of the anomeric temporary protecting group must be carefully considered because it should retain intact during the whole synthetic manipulation, and it should be chemoselectively removable without affecting other functional groups at a late stage in the synthesis. Etherate groups are the most widely used temporary protecting groups at the anomeric center, generally including allyl ethers, MP (p-methoxyphenyl) ethers, benzyl ethers, PMB (p-methoxybenzyl) eithers, and silyl ethers. This chapter provides a comprehensive review on their formation, cleavage, and applications in the synthesis of complex carbohydrates.
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Affiliation(s)
- Wei Li
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China.
| | - Biao Yu
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China.
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Leitner GR, Wenzel TJ, Marshall N, Gates EJ, Klegeris A. Targeting toll-like receptor 4 to modulate neuroinflammation in central nervous system disorders. Expert Opin Ther Targets 2019; 23:865-882. [PMID: 31580163 DOI: 10.1080/14728222.2019.1676416] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Introduction: Adverse immune activation contributes to many central nervous system (CNS) disorders. All main CNS cell types express toll-like receptor 4 (TLR 4). This receptor is critical for a myriad of immune functions such as cytokine secretion and phagocytic activity of microglia; however, imbalances in TLR 4 activation can contribute to the progression of neurodegenerative diseases. Areas covered: We considered available evidence implicating TLR 4 activation in the following CNS pathologies: Alzheimer's disease, Parkinson's disease, ischemic stroke, traumatic brain injury, multiple sclerosis, multiple systems atrophy, and Huntington's disease. We reviewed studies reporting effects of TLR 4-specific antagonists and agonists in models of peripheral and CNS diseases from the perspective of possible future use of TLR 4 ligands in CNS disorders. Expert opinion: TLR 4-specific antagonists could suppress neuroinflammation by reducing overproduction of inflammatory mediators; however, they may interfere with protein clearance mechanisms and myelination. Agonists that specifically activate myeloid differentiation primary-response protein 88 (MyD88)-independent pathway of TLR 4 signaling could facilitate beneficial glial phagocytic activity with limited activity as inducers of proinflammatory mediators. Deciphering the disease stage-specific involvement of TLR 4 in CNS pathologies is crucial for the future clinical development of TLR 4 agonists and antagonists.
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Affiliation(s)
- Gunnar R Leitner
- Department of Biology, University of British Columbia Okanagan Campus , Kelowna , British Columbia , Canada
| | - Tyler J Wenzel
- Department of Biology, University of British Columbia Okanagan Campus , Kelowna , British Columbia , Canada
| | - Nick Marshall
- Department of Biology, University of British Columbia Okanagan Campus , Kelowna , British Columbia , Canada
| | - Ellen J Gates
- Department of Biology, University of British Columbia Okanagan Campus , Kelowna , British Columbia , Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus , Kelowna , British Columbia , Canada
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Achek A, Shah M, Seo JY, Kwon HK, Gui X, Shin HJ, Cho EY, Lee BS, Kim DJ, Lee SH, Yoo TH, Kim MS, Choi S. Linear and Rationally Designed Stapled Peptides Abrogate TLR4 Pathway and Relieve Inflammatory Symptoms in Rheumatoid Arthritis Rat Model. J Med Chem 2019; 62:6495-6511. [PMID: 31283217 DOI: 10.1021/acs.jmedchem.9b00061] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A mounting evidence exists for the despicable role of the aberrant immune response in the pathogenesis of rheumatoid arthritis (RA), where toll-like receptor 4 (TLR4) can activate synovial fibroblasts that lead to the chronic inflammation and joint destruction, thus making TLR4 a potent drug target in RA. We report that novel TLR4-antagonizing peptide, PIP2, inhibits the induction of inflammatory biomarkers in vitro as well as in vivo. Systemically, PIP2 inhibits the lipopolysaccharide (LPS)-elicited TNF-α, IL-6, and IL-12p40 in a mouse model. The rationally designed cyclic derivative, cPIP2, is capable of inhibiting LPS-induced proinflammatory cytokines at significantly lower concentration as compared to PIP2 (PIP2 IC50 = 20 μM, cPIP2 IC50 = 5 μM). Finally, cPIP2 was able to relieve the inflammatory symptoms and synovial tissue destruction in the RA rat model. Cumulatively, these data suggest that PIP2 and cPIP2 hold strong promise for the development of peptide-based immunotherapeutics that could be of great value in curbing TLR-related immune complications including RA.
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Affiliation(s)
- Asma Achek
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
| | - Masaud Shah
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
| | - Ji Young Seo
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
| | - Hyuk-Kwon Kwon
- Department of Orthopedics and Rehabilitation , Yale University School of Medicine , New Haven , Connecticut 06520-8071 , United States
| | - Xiangai Gui
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
| | - Hyeon-Jun Shin
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
| | - Eun-Young Cho
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
| | - Byeong Sung Lee
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
| | - Dong-Jin Kim
- Division of Nephrology, Department of Internal Medicine , Kyung Hee University Hospital at Gangdong , Seoul 05278 , Korea
| | - Sang Ho Lee
- Division of Nephrology, Department of Internal Medicine , Kyung Hee University Hospital at Gangdong , Seoul 05278 , Korea
| | - Tae Hyeon Yoo
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
| | - Moon Suk Kim
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
| | - Sangdun Choi
- Department of Molecular Science and Technology , Ajou University , Suwon 16499 , Korea
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Hayashi N, Furue Y, Kai D, Yamada N, Yamamoto H, Nakano T, Oda M. Sulfated vizantin suppresses mucin layer penetration dependent on the flagella motility of Pseudomonas aeruginosa PAO1. PLoS One 2018; 13:e0206696. [PMID: 30383847 PMCID: PMC6211736 DOI: 10.1371/journal.pone.0206696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 10/17/2018] [Indexed: 12/29/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes severe infections, such as pneumonia and bacteremia. Several studies demonstrated that flagellar motility is an important virulence factor for P. aeruginosa infection. In this study, we determined whether sulfated vizantin affects P. aeruginosa flagellar motility in the absence of direct antimicrobial activity. We found that 100 μM sulfated vizantin suppressed P. aeruginosa PAO1 from penetrating through an artificial mucin layer by affecting flagellar motility, although it did not influence growth nor bacterial protease activity. To further clarify the mechanism in which sulfated vizantin suppresses the flagellar motility of P. aeruginosa PAO1, we examined the effects of sulfated vizantin on the composition of the flagellar filament and mRNA expression of several flagella-related genes, finding that sulfated vizantin did not influence the composition of the flagellar complex (fliC, motA, and motB) in P. aeruginosa PAO1, but significantly decreased mRNA expression of the chemotaxis-related genes cheR1, cheW, and cheZ. These results indicated that sulfated vizantin is an effective inhibitor of flagellar motility in P. aeruginosa.
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Affiliation(s)
- Naoki Hayashi
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Yui Furue
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Daichi Kai
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Noriteru Yamada
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Hirofumi Yamamoto
- Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Takashi Nakano
- Department of Microbiology and Infection Control, Osaka Medical College, Osaka, Japan
| | - Masataka Oda
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Kyoto, Japan
- * E-mail:
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Recent advances on Toll-like receptor 4 modulation: new therapeutic perspectives. Future Med Chem 2018; 10:461-476. [PMID: 29380635 DOI: 10.4155/fmc-2017-0172] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Activation or inhibition of TLR4 by small molecules will provide in the next few years a new generation of therapeutics. TLR4 stimulation (agonism) by high-affinity ligands mimicking lipid A gave vaccine adjuvants with improved specificity and efficacy that have been licensed and entered into the market. TLR4 inhibition (antagonism) prevents cytokine production at a very early stage; this is in principle a more efficient method to block inflammatory diseases compared to cytokines neutralization by antibodies. Advances in TLR4 modulation by drug-like small molecules achieved in the last years are reviewed. Recently discovered TLR4 agonists and antagonists of natural and synthetic origin are presented, and their mechanism of action and structure-activity relationship are discussed.
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Takenaka S, Oda M, Domon H, Ohsumi T, Suzuki Y, Ohshima H, Yamamoto H, Terao Y, Noiri Y. Vizantin inhibits bacterial adhesion without affecting bacterial growth and causes Streptococcus mutans biofilm to detach by altering its internal architecture. Biochem Biophys Res Commun 2016; 480:173-179. [PMID: 27742478 DOI: 10.1016/j.bbrc.2016.10.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 10/09/2016] [Indexed: 12/14/2022]
Abstract
An ideal antibiofilm strategy is to control both in the quality and quantity of biofilm while maintaining the benefits derived from resident microflora. Vizantin, a recently developed immunostimulating compound, has also been found to have antibiofilm property. This study evaluated the influence on biofilm formation of Streptococcus mutans in the presence of sulfated vizantin and biofilm development following bacterial adhesion on a hydroxyapatite disc coated with sulfated vizantin. Supplementation with sulfated vizantin up to 50 μM did not affect either bacterial growth or biofilm formation, whereas 50 μM sulfated vizantin caused the biofilm to readily detach from the surface. Sulfated vizantin at the concentration of 50 μM upregulated the expression of the gtfB and gtfC genes, but downregulated the expression of the gtfD gene, suggesting altered architecture in the biofilm. Biofilm development on the surface coated with sulfated vizantin was inhibited depending on the concentration, suggesting prevention from bacterial adhesion. Among eight genes related to bacterial adherence in S. mutans, expression of gtfB and gtfC was significantly upregulated, whereas the expression of gtfD, GbpA and GbpC was downregulated according to the concentration of vizantin, especially with 50 μM vizantin by 0.8-, 0.4-, and 0.4-fold, respectively. These findings suggest that sulfated vizantin may cause structural degradation as a result of changing gene regulation related to bacterial adhesion and glucan production of S. mutans.
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Affiliation(s)
- Shoji Takenaka
- Division of Cariology, Operative Dentistry and Endodontics, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata, 951-8514, Japan.
| | - Masataka Oda
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata, 951-8514, Japan
| | - Hisanori Domon
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata, 951-8514, Japan
| | - Tatsuya Ohsumi
- Division of Cariology, Operative Dentistry and Endodontics, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata, 951-8514, Japan
| | - Yuki Suzuki
- Division of Cariology, Operative Dentistry and Endodontics, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata, 951-8514, Japan
| | - Hayato Ohshima
- Division of Anatomy and Cell Biology of Hard Tissue, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata, 951-8514, Japan
| | - Hirofumi Yamamoto
- Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima, 770-8514, Japan
| | - Yutaka Terao
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata, 951-8514, Japan
| | - Yuichiro Noiri
- Division of Cariology, Operative Dentistry and Endodontics, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata, 951-8514, Japan
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