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Sommer K, Zollfrank C. Block Copolysaccharides from Methylated and Acetylated Cellulose and Starch. Biomacromolecules 2022; 23:2280-2289. [DOI: 10.1021/acs.biomac.1c01673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Korbinian Sommer
- Chair for Biogenic Polymers, TUM Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Schulgasse 16, Straubing 94315, Germany
| | - Cordt Zollfrank
- Chair for Biogenic Polymers, TUM Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Schulgasse 16, Straubing 94315, Germany
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2
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Stereoselective synthesis of a 4-⍺-glucoside of valienamine and its X-ray structure in complex with Streptomyces coelicolor GlgE1-V279S. Sci Rep 2021; 11:13413. [PMID: 34183716 PMCID: PMC8238978 DOI: 10.1038/s41598-021-92554-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023] Open
Abstract
Glycoside hydrolases (GH) are a large family of hydrolytic enzymes found in all domains of life. As such, they control a plethora of normal and pathogenic biological functions. Thus, understanding selective inhibition of GH enzymes at the atomic level can lead to the identification of new classes of therapeutics. In these studies, we identified a 4-⍺-glucoside of valienamine (8) as an inhibitor of Streptomyces coelicolor (Sco) GlgE1-V279S which belongs to the GH13 Carbohydrate Active EnZyme family. The results obtained from the dose-response experiments show that 8 at a concentration of 1000 µM reduced the enzyme activity of Sco GlgE1-V279S by 65%. The synthetic route to 8 and a closely related 4-⍺-glucoside of validamine (7) was achieved starting from readily available D-maltose. A key step in the synthesis was a chelation-controlled addition of vinylmagnesium bromide to a maltose-derived enone intermediate. X-ray structures of both 7 and 8 in complex with Sco GlgE1-V279S were solved to resolutions of 1.75 and 1.83 Å, respectively. Structural analysis revealed the valienamine derivative 8 binds the enzyme in an E2 conformation for the cyclohexene fragment. Also, the cyclohexene fragment shows a new hydrogen-bonding contact from the pseudo-diaxial C(3)-OH to the catalytic nucleophile Asp 394 at the enzyme active site. Asp 394, in fact, forms a bidentate interaction with both the C(3)-OH and C(7)-OH of the inhibitor. In contrast, compound 7 disrupts the catalytic sidechain interaction network of Sco GlgE1-V279S via steric interactions resulting in a conformation change in Asp 394. These findings will have implications for the design other aminocarbasugar-based GH13-inhibitors and will be useful for identifying more potent and selective inhibitors.
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Fu F, Fan Y, Chen L, Zhang J, Li J. Water Solubility and Surface Activity of Alkoxyethyl β-d-Maltosides. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:8330-8340. [PMID: 32677832 DOI: 10.1021/acs.jafc.0c00349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Green surfactants alkyl glycosides are key to solve the inherent problem of water solubility due to their commercial application and extensive scientific research. Based on the enhancement strategy of hydrophilicity through the reconstruction of the conventional alkyl β-d-maltoside by introducing an oxyethyl group (-OCH2CH2-), d-maltose was used to prepare a series of nonionic disaccharide-based surfactants alkoxyethyl β-d-maltosides (4a-h, n = 6-16) so that the related water solubility was effectively improved, while the corresponding surface activity and other excellent properties were still maintained. Their physicochemical properties, including water solubility, surface activity, moisture absorption, and thermotropic liquid crystalline behavior, were investigated. The liquid crystal texture of alkoxyethyl β-d-maltosides (n = 7-16) has a fan-shaped focal conic texture. Furthermore, decoxyethyl β-d-maltoside had the strongest foaming characteristic and the best foam stability. Moreover, dodecoxyethyl β-d-maltoside (4f, n =12) had stronger emulsifying activity in the rapeseed oil/water system. Finally, CTAC/4f binary surfactants had an obvious synergistic effect. Such β-d-maltosides should have good application prospects in the future.
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Affiliation(s)
- Fang Fu
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
| | - Yulin Fan
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
| | - Langqiu Chen
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
| | - Jing Zhang
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
| | - Jiping Li
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
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Chen C, Fan Y, Cao C, Wang H, Fan Y, Jiang J, Wei Z, Maurin G, Su C. Dynamic Coordination Chemistry of Fluorinated Zr‐MOFs: Synthetic Control and Reassembly/Disassembly Beyond de Novo Synthesis to Tune the Structure and Property. Chemistry 2020; 26:8254-8261. [DOI: 10.1002/chem.202001052] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Indexed: 01/09/2023]
Affiliation(s)
- Cheng‐Xia Chen
- MOE Laboratory of Bioinorganic and Synthetic ChemistryLehn Institute of Functional Materials, School of ChemistrySun Yat-Sen University Guangzhou 510275 China
| | - Yan‐Zhong Fan
- MOE Laboratory of Bioinorganic and Synthetic ChemistryLehn Institute of Functional Materials, School of ChemistrySun Yat-Sen University Guangzhou 510275 China
| | - Chen‐Chen Cao
- MOE Laboratory of Bioinorganic and Synthetic ChemistryLehn Institute of Functional Materials, School of ChemistrySun Yat-Sen University Guangzhou 510275 China
| | - Hai‐Ping Wang
- MOE Laboratory of Bioinorganic and Synthetic ChemistryLehn Institute of Functional Materials, School of ChemistrySun Yat-Sen University Guangzhou 510275 China
| | - Ya‐Nan Fan
- MOE Laboratory of Bioinorganic and Synthetic ChemistryLehn Institute of Functional Materials, School of ChemistrySun Yat-Sen University Guangzhou 510275 China
| | - Ji‐Jun Jiang
- MOE Laboratory of Bioinorganic and Synthetic ChemistryLehn Institute of Functional Materials, School of ChemistrySun Yat-Sen University Guangzhou 510275 China
| | - Zhang‐Wen Wei
- MOE Laboratory of Bioinorganic and Synthetic ChemistryLehn Institute of Functional Materials, School of ChemistrySun Yat-Sen University Guangzhou 510275 China
| | - Guillaume Maurin
- Institut Charles Gerhardt Montpellier UMR 5253 CNRSUniversité de Montpellier Place E. Bataillon 34095 Montpellier Cedex 05 France
| | - Cheng‐Yong Su
- MOE Laboratory of Bioinorganic and Synthetic ChemistryLehn Institute of Functional Materials, School of ChemistrySun Yat-Sen University Guangzhou 510275 China
- State Key Laboratory of Applied Organic ChemistryLanzhou University Lanzhou 730000 China
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5
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Uhrig ML, Lantaño B, Postigo A. Synthetic strategies for fluorination of carbohydrates. Org Biomol Chem 2019; 17:5173-5189. [DOI: 10.1039/c9ob00405j] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Different synthetic strategies for accomplishing regio- and stereoselective fluorinations of carbohydrate scaffolds are discussed in light of the biological implications arising from such substitutions.
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Affiliation(s)
- María Laura Uhrig
- Universidad de Buenos Aires
- Facultad de Ciencias Exactas y Naturales
- Departamento de Química Orgánica
- C1428EG Buenos Aires
- Argentina
| | - Beatriz Lantaño
- Departmento de Química Orgánica
- Facultad de Farmacia y Bioquímica
- Universidad de Buenos Aires
- Junin 954 CP1113-Buenos Aires
- Argentina
| | - Al Postigo
- Departmento de Química Orgánica
- Facultad de Farmacia y Bioquímica
- Universidad de Buenos Aires
- Junin 954 CP1113-Buenos Aires
- Argentina
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6
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Dalvit C, Vulpetti A. Ligand-Based Fluorine NMR Screening: Principles and Applications in Drug Discovery Projects. J Med Chem 2018; 62:2218-2244. [DOI: 10.1021/acs.jmedchem.8b01210] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
| | - Anna Vulpetti
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, 4002 Basel, Switzerland
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7
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Affiliation(s)
- Zhenchuang Xu
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| | - Chao Liu
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| | - Shujuan Zhao
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| | - Si Chen
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| | - Yanchuan Zhao
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
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8
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Namavari M, Gowrishankar G, Srinivasan A, Gambhir SS, Haywood T, Beinat C. A novel synthesis of 6''-[ 18 F]-fluoromaltotriose as a PET tracer for imaging bacterial infection. J Labelled Comp Radiopharm 2018; 61:408-414. [PMID: 29314161 DOI: 10.1002/jlcr.3601] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 11/06/2022]
Abstract
The aim of this study was to develop a positron emission tomography (PET) tracer to visualize and monitor therapeutic response to bacterial infections. In our continued efforts to find maltose based PET tracers that can image bacterial infections, we have designed and prepared 6''-[18 F]fluoromaltotriose as a second generation PET imaging tracer targeting the maltodextrin transporter of bacteria. We have developed methods to synthesize 6''-deoxy-6''-[18 F]fluoro-α-D-glucopyranosyl-(1-4)-O-α-D-glucopyranosyl-(1-4)-O-D-glucopyranose (6''-[18 F]-fluoromaltotriose) as a bacterial infection PET imaging agent. 6''-[18 F]fluoromaltotriose was prepared from precursor, 2'',3'',4''-tri-O-acetyl-6''-O-nosyl-α-D-glucopyranosyl-(1-4)-O-2',3',6'-tri-O-acetyl-α-D-glucopyranosyl-(1-4)-1,2,3,6-tetra-O-acetyl-D-glucopyranose (per-O-acetyl-6''-O-nosyl-maltotriose 4). This method utilizes the reaction between precursor 4 and anhydrous [18 F]KF/Kryptofix 2.2.2 in dimethylformamide (DMF) at 85°C for 10 minutes to yield per-O-acetyl-6''-deoxy-6-'' [18 F]-fluoromaltotriose (7). Successive acidic and basic hydrolysis of the acetyl protecting groups in 7 produced 6''-[18 F]fluoromaltotriose (8). Also, cold 6''- [19 F]fluoromaltotriose was prepared from per-O-acetyl-6''-hydroxymaltotriose via a diethylaminosulfur trifluoride reaction followed by a basic hydrolysis. A successful synthesis of 6''-[18 F]-fluoromaltotriose has been accomplished in 8 ± 1.2% radiochemical yield (decay corrected). Total synthesis time was 120 minutes. Serum stability of 6''-[18 F]fluoromaltotriose at 37°C indicated that 6''-[18 F]-fluoromaltotriose remained intact up to 2 hours. In conclusion, we have successfully synthesized 6''-[18 F]-fluoromaltotriose via direct fluorination of an appropriate precursor of a protected maltotriose.
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Affiliation(s)
- Mohammad Namavari
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bioengineering Bio-X Program, Stanford University, Stanford, California, USA
| | - Gayatri Gowrishankar
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bioengineering Bio-X Program, Stanford University, Stanford, California, USA
| | - Ananth Srinivasan
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bioengineering Bio-X Program, Stanford University, Stanford, California, USA
| | - Sanjiv S Gambhir
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bioengineering Bio-X Program, Stanford University, Stanford, California, USA
| | - Thomas Haywood
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bioengineering Bio-X Program, Stanford University, Stanford, California, USA
| | - Corinne Beinat
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bioengineering Bio-X Program, Stanford University, Stanford, California, USA
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Dalvit C, Knapp S. 19 F NMR isotropic chemical shift for efficient screening of fluorinated fragments which are racemates and/or display multiple conformers. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:1091-1095. [PMID: 28762528 DOI: 10.1002/mrc.4640] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/12/2017] [Accepted: 07/29/2017] [Indexed: 06/07/2023]
Abstract
Fluorine ligand-based NMR spectroscopy is now an established method for performing binding screening against a macromolecular target. Typically, the transverse relaxation rate of the fluorine signals is monitored in the absence and presence of the target. However, useful structural information can sometimes be obtained from the analysis of the fluorine isotropic chemical shift. This is particularly relevant for molecules that are racemates and/or display multiple conformers. The large difference in fluorine isotropic chemical shift between free and bound state deriving mainly from the breaking and/or making of intramolecular and/or intermolecular hydrogen bonds allows the detection of very weak affinity ligands. According to our experimental results, racemates should always be included in the generation of the fluorinated fragment libraries. The selection or the availability of only one of the enantiomers for the fluorinated screening library could result in missing relevant chemical scaffold motifs.
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Affiliation(s)
- Claudio Dalvit
- Faculty of Science, University of Neuchatel, 2000, Neuchatel, Switzerland
| | - Stefan Knapp
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Riedberg Campus, 60438, Frankfurt, Germany
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium, Oxford University, Oxford, OX3 7DQ, UK
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Patel K, Song F, Andreana PR. Synthesis of substrate analogues as potential inhibitors for Mycobacterium tuberculosis enzyme MshC. Carbohydr Res 2017; 453-454:10-18. [PMID: 29107814 DOI: 10.1016/j.carres.2017.10.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/20/2017] [Accepted: 10/21/2017] [Indexed: 01/03/2023]
Abstract
Mycothiol cysteine ligase (MshC) is a key enzyme in the mycothiol (MSH) biosynthesis and a promising target for developing new anti-mycobacterial compounds. Herein, we report on the synthesis of substrate analogues, as potential inhibitors, for the MshC enzyme. The target molecules were synthesized employing a Schmidt glycosylation strategy using an enantiomerically pure inositol acceptor and 2-deoxy trichloroacetimidate glycosyl donors with glycosylation yields greater than 70% and overall yields >5%. The inositol acceptor was obtained via chiral resolution of (±)-myo-inositol.
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Affiliation(s)
- Krishnakant Patel
- Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, The University of Toledo, 2801 W. Bancroft Street, Toledo, Ohio 43606, United States
| | - Fengling Song
- Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, The University of Toledo, 2801 W. Bancroft Street, Toledo, Ohio 43606, United States
| | - Peter R Andreana
- Department of Chemistry and Biochemistry and School of Green Chemistry and Engineering, The University of Toledo, 2801 W. Bancroft Street, Toledo, Ohio 43606, United States.
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Dalvit C, Piotto M. 19 F NMR transverse and longitudinal relaxation filter experiments for screening: a theoretical and experimental analysis. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:106-114. [PMID: 27514284 DOI: 10.1002/mrc.4500] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 08/09/2016] [Indexed: 06/06/2023]
Abstract
Ligand-based 19 F NMR screening represents an efficient approach for performing binding assays. The high sensitivity of the methodology to receptor binding allows the detection of weak affinity ligands. The observable NMR parameters that are typically used are the 19 F transverse relaxation rate and isotropic chemical shift. However, there are few cases where the 19 F longitudinal relaxation rate should also be used. A theoretical and experimental analysis of the 19 F NMR transverse and longitudinal relaxation rates at different magnetic fields is presented along with proposed methods for improving the sensitivity and dynamic range of these experiments applied to fragment-based screening. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Claudio Dalvit
- Faculty of Science, University of Neuchatel, Neuchatel, Switzerland
- IDD/SDI, Sanofi, Vitry-sur-Seine, France
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12
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Thanna S, Lindenberger JJ, Gaitonde VV, Ronning DR, Sucheck SJ. Synthesis of 2-deoxy-2,2-difluoro-α-maltosyl fluoride and its X-ray structure in complex with Streptomyces coelicolor GlgEI-V279S. Org Biomol Chem 2016; 13:7542-50. [PMID: 26072729 DOI: 10.1039/c5ob00867k] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Streptomyces coelicolor (Sco) GlgEI is a glycoside hydrolase involved in α-glucan biosynthesis and can be used as a model enzyme for structure-based inhibitor design targeting Mycobacterium tuberculosis (Mtb) GlgE. The latter is a genetically validated drug target for the development of anti-Tuberculosis (TB) treatments. Inhibition of Mtb GlgE results in a lethal buildup of the GlgE substrate maltose-1-phosphate (M1P). However, Mtb GlgE is difficult to crystallize and affords lower resolution X-ray structures. Sco GlgEI-V279S on the other hand crystallizes readily, produces high resolution X-ray data, and has active site topology identical to Mtb GlgE. We report the X-ray structure of Sco GlgEI-V279S in complex with 2-deoxy-2,2-difluoro-α-maltosyl fluoride (α-MTF, 5) at 2.3 Å resolution. α-MTF was designed as a non-hydrolysable mimic of M1P to probe the active site of GlgE1 prior to covalent bond formation without disruption of catalytic residues. The α-MTF complex revealed hydrogen bonding between Glu423 and the C1F which provides evidence that Glu423 functions as proton donor during catalysis. Further, hydrogen bonding between Arg392 and the axial C2 difluoromethylene moiety of α-MTF was observed suggesting that the C2 position tolerates substitution with hydrogen bond acceptors. The key step in the synthesis of α-MDF was transformation of peracetylated 2-fluoro-maltal 1 into peracetylated 2,2-difluoro-α-maltosyl fluoride 2 in a single step via the use of Selectfluor®.
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Affiliation(s)
- Sandeep Thanna
- Department of Chemistry and Biochemistry, The University of Toledo, 2801 W. Bancroft Street, MS602, Toledo, OH, USA 43606.
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Synthesis of [¹⁸F]-labelled maltose derivatives as PET tracers for imaging bacterial infection. Mol Imaging Biol 2015; 17:168-76. [PMID: 25277604 DOI: 10.1007/s11307-014-0793-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE To develop novel positron emission tomography (PET) agents for visualization and therapy monitoring of bacterial infections. PROCEDURES It is known that maltose and maltodextrins are energy sources for bacteria. Hence, (18)F-labelled maltose derivatives could be a valuable tool for imaging bacterial infections. We have developed methods to synthesize 4-O-(α-D-glucopyranosyl)-6-deoxy-6-[(18)F]fluoro-D-glucopyranoside (6-[(18)F]fluoromaltose) and 4-O-(α-D-glucopyranosyl)-1-deoxy-1-[(18)F]fluoro-D-glucopyranoside (1-[(18)F]fluoromaltose) as bacterial infection PET imaging agents. 6-[(18)F]fluoromaltose was prepared from precursor 1,2,3-tri-O-acetyl-4-O-(2',3',-di-O-acetyl-4',6'-benzylidene-α-D-glucopyranosyl)-6-deoxy-6-nosyl-D-glucopranoside (5). The synthesis involved the radio-fluorination of 5 followed by acidic and basic hydrolysis to give 6-[(18)F]fluoromaltose. In an analogous procedure, 1-[(18)F]fluoromaltose was synthesized from 2,3, 6-tri-O-acetyl-4-O-(2',3',4',6-tetra-O-acetyl-α-D-glucopyranosyl)-1-deoxy-1-O-triflyl-D-glucopranoside (9). Stability of 6-[(18)F]fluoromaltose in phosphate-buffered saline (PBS) and human and mouse serum at 37 °C was determined. Escherichia coli uptake of 6-[(18)F]fluoromaltose was examined. RESULTS A reliable synthesis of 1- and 6-[(18)F]fluoromaltose has been accomplished with 4-6 and 5-8% radiochemical yields, respectively (decay-corrected with 95 % radiochemical purity). 6-[(18)F]fluoromaltose was sufficiently stable over the time span needed for PET studies (∼96% intact compound after 1-h and ∼65% after 2-h incubation in serum). Bacterial uptake experiments indicated that E. coli transports 6-[(18)F]fluoromaltose. Competition assays showed that the uptake of 6-[(18)F]fluoromaltose was completely blocked by co-incubation with 1 mM of the natural substrate maltose. CONCLUSION We have successfully synthesized 1- and 6-[(18)F]fluoromaltose via direct fluorination of appropriate protected maltose precursors. Bacterial uptake experiments in E. coli and stability studies suggest a possible application of 6-[(18)F]fluoromaltose as a new PET imaging agent for visualization and monitoring of bacterial infections.
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Lindhorst TK. Multivalent glycosystems for nanoscience. Beilstein J Org Chem 2014; 10:2345-7. [PMID: 25383104 PMCID: PMC4222442 DOI: 10.3762/bjoc.10.244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 09/24/2014] [Indexed: 12/15/2022] Open
Affiliation(s)
- Thisbe K Lindhorst
- Otto Diels Institute of Organic Chemistry, Christiana Albertina University of Kiel, Otto-Hahn-Platz 3/4, 24098 Kiel, Germany
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Dalvit C, Invernizzi C, Vulpetti A. Fluorine as a hydrogen-bond acceptor: experimental evidence and computational calculations. Chemistry 2014; 20:11058-68. [PMID: 25044441 DOI: 10.1002/chem.201402858] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Indexed: 12/19/2022]
Abstract
Hydrogen-bonding interactions play an important role in many chemical and biological systems. Fluorine acting as a hydrogen-bond acceptor in intermolecular and intramolecular interactions has been the subject of many controversial discussions and there are different opinions about it. Recently, we have proposed a correlation between the propensity of fluorine to be involved in hydrogen bonds and its (19)F NMR chemical shift. We now provide additional experimental and computational evidence for this correlation. The strength of hydrogen-bond complexes involving the fluorine moieties CH2F, CHF2, and CF3 was measured and characterized in simple systems by using established and novel NMR methods and compared to the known hydrogen-bond complex formed between acetophenone and p-fluorophenol. Implications of these results for (19)F NMR screening are analyzed in detail. Computed values of the molecular electrostatic potential at the different fluorine atoms and the analysis of the electron density topology at bond critical points correlate well with the NMR results.
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Affiliation(s)
- Claudio Dalvit
- University of Neuchâtel, Faculty of Science, 2000 Neuchâtel (Switzerland).
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Albler C, Schmid W. Synthetic Routes towards Fluorine-Containing Amino Sugars: Synthesis of Fluorinated Analogues of Tomosamine and 4-Amino-4-deoxyarabinose. European J Org Chem 2014. [DOI: 10.1002/ejoc.201301614] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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17
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Synthesis of a C-phosphonate mimic of maltose-1-phosphate and inhibition studies on Mycobacterium tuberculosis GlgE. Bioorg Med Chem 2014; 22:1404-11. [PMID: 24461562 DOI: 10.1016/j.bmc.2013.12.058] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/16/2013] [Accepted: 12/26/2013] [Indexed: 01/06/2023]
Abstract
The emergence of extensively drug-resistant tuberculosis (XDR-TB) necessitates the need to identify new anti-tuberculosis drug targets as well as to better understand essential biosynthetic pathways. GlgE is a Mycobacterium tuberculosis (Mtb) encoded maltosyltransferase involved in α-glucan biosynthesis. Deletion of GlgE in Mtb results in the accumulation of M1P within cells leading to rapid death of the organism. To inhibit GlgE a maltose-C-phosphonate (MCP) 13 was designed to act as an isosteric non-hydrolysable mimic of M1P. MCP 13, the only known inhibitor of Mtb GlgE, was successfully synthesized using a Wittig olefination as a key step in transforming maltose to the desired product. MCP 13 inhibited Mtb GlgE with an IC₅₀=230 ± 24 μM determined using a coupled enzyme assay which measures orthophosphate release. The requirement of M1P for the assay necessitated the development of an expedited synthetic route to M1P from an intermediate used in the MCP 13 synthesis. In conclusion, we designed a substrate analogue of M1P that is the first to exhibit Mtb GlgE inhibition.
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Vulpetti A, Dalvit C. Design and generation of highly diverse fluorinated fragment libraries and their efficient screening with improved (19) F NMR methodology. ChemMedChem 2013; 8:2057-69. [PMID: 24127294 DOI: 10.1002/cmdc.201300351] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Indexed: 12/11/2022]
Abstract
Fragment screening performed with (19) F NMR spectroscopy is becoming increasingly popular in drug discovery projects. With this approach, libraries of fluorinated fragments are first screened using the direct-mode format of the assay. The choice of fluorinated motifs present in the library is fundamental in order to ensure a large coverage of chemical space and local environment of fluorine (LEF). Mono- and poly-fluorinated fragments to be included in the libraries for screening are selected from both in-house and commercial collections, and those that are ad hoc designed and synthesized. Additional fluorinated motifs to be included in the libraries derive from the fragmentation of compounds in development and launched on the market, and compounds contained in other databases (such as Integrity, PDB and ChEMBL). Complex mixtures of highly diverse fluorine motifs can be rapidly screened and deconvoluted in the same NMR tube with a novel on the fly combined procedure for the identification of the active molecule(s). Issues and problems encountered in the design, generation and screening of diverse fragment libraries of fluorinated compounds with (19) F NMR spectroscopy are analyzed and technical solutions are provided to overcome them. The versatile screening methodology described here can be efficiently applied in laboratories with limited NMR setup and could potentially lead to the increasing role of (19) F NMR in the hit identification and lead optimization phases of drug discovery projects.
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Affiliation(s)
- Anna Vulpetti
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, 4002 Basel (Switzerland).
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Dalvit C, Vulpetti A. Technical and practical aspects of (19) F NMR-based screening: toward sensitive high-throughput screening with rapid deconvolution. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50:592-597. [PMID: 22821476 DOI: 10.1002/mrc.3842] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 06/04/2012] [Accepted: 06/12/2012] [Indexed: 06/01/2023]
Abstract
The technical and practical aspects of (19) F NMR-based screening against a macromolecular target are analyzed in detail. A novel method utilizing the relaxation of (19) F homonuclear double quantum coherence is proposed for performing NMR-based binding assays in a direct- or competition-mode format. A combined strategy based on (19) F NMR chemical shift prediction, 2D (19) F NMR DOSY, and 2D (19) F-(1) H NMR long-range COSY experiments is presented for the deconvolution of complex mixtures of fluorinated molecules generated by either addition of single compounds or by chemical synthesis. The approaches presented here allow the screening of complex mixtures, even in the case where the exact composition is not known, and the rapid identification of the binders contained in the mixtures.
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Affiliation(s)
- Claudio Dalvit
- Department of Chemistry, University of Neuchâtel, CH 2000, Neuchâtel, Switzerland.
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