The Experts below are selected from a list of 124923 Experts worldwide ranked by ideXlab platform
W.d. Lubell - One of the best experts on this subject based on the ideXlab platform.
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Insertion of multiple alpha-amino gamma-Lactam (Agl) residues into a peptide sequence by solid-phase synthesis on synphase lanterns.
Biopolymers, 2010Co-Authors: Luisa Ronga, A.g. Jamieson, K. Beauregard, C. Quiniou, S. Chemtob, W.d. LubellAbstract:The insertion of Lactams into peptide analogs can enhance potency and improve receptor selectivity. The synthesis of Lactam-bridged peptide sequences has been accomplished by a solid-phase approach on SynPhase lanterns using cyclic (R)- and (S)-oxathiazinane ester (2) to annulate the amino Lactam residue onto the peptide chain. Parallel synthesis of alpha-amino gamma-Lactam analogs of the allosteric modulator of IL-1 receptor 101.10 (D-Arg-D-Tyr-D-Thr-D-Val-D-Glu-D-Leu-D-Ala: rytvela) was performed by split-mix chemistry on the lanterns. In particular, the double insertion of alpha-amino gamma-Lactams in the same peptide sequence has been accomplished by this effective method for the solid-supported combinatorial synthesis of Lactam-bridged peptides. Peptides bearing an Agl residue exhibited curve shapes indicative of turn conformations in their circular dichroism spectra.
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positional scanning for peptide secondary structure by systematic solid phase synthesis of amino Lactam peptides
Journal of the American Chemical Society, 2009Co-Authors: Andrew G Jamieson, K. Beauregard, C. Quiniou, S. Chemtob, Nicolas Boutard, Mandar S Bodas, W.d. LubellAbstract:Incorporation of amino Lactams into biologically active peptides has been commonly used to restrict conformational mobility, enhance selectivity, and increase potency. A solid-phase method using a Fmoc-protection strategy has been developed for the systematic synthesis of peptides containing configurationally defined α- and β-amino γ-Lactams. N-Alkylation of N-silyl peptides with five- and six-member cyclic sulfamidates 9 and 8 minimized bis-alkylation and provided N-alkyl peptides, which underwent Lactam annulation under microwave heating. Employing this solid-phase protocol on the growth hormone secretagogue GHRP-6, as well as on the allosteric modulator of the IL-1 receptor 101.10, has furnished 16 Lactam derivatives and validated the effectiveness of this approach on peptides bearing aliphatic, aromatic, branched, charged, and heteroatomic side chains. The binding affinity IC50 values of the GHRP-6 Lactam analogues on both the GHS-R1a and CD36 receptors are reported as well as inhibition of thymocyte ...
Mikel Oiarbide - One of the best experts on this subject based on the ideXlab platform.
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asymmetric synthesis of β Lactams by staudinger ketene imine cycloaddition reaction
European Journal of Organic Chemistry, 1999Co-Authors: Claudio Palomo, Jesus Mari Aizpurua, I Ganboa, Mikel OiarbideAbstract:[2 + 2] Cycloaddition reactions between ketenes, bearing amino-, oxy-, or halo- groups, and imines are recognized as being amongst the most important and direct routes to β-Lactams. Alkyl-substituted ketenes also furnished the corresponding β-Lactams upon reaction with activated imines (iminoesters). In general, ketenes are generated from the appropriate acid chloride and a tertiary amine. The major or sole product of the cycloaddition is usually the cis-β-Lactam, although a few exceptions showing trans selectivity are known. In this way β-Lactams with a widely varying substitution pattern at the C-3 and C-4 positions of the ring are constructed stereoselectively. The diastereoselection of the cycloaddition process can be controlled with variable success from chiral groups attached to either the ketene or the imine component, or alternatively to both. This method, in turn, has proved to be valuable for the synthesis of precursors of important β-Lactam antibiotics, and new successful applications can be expected in the near future.
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Asymmetric Synthesis of β‐Lactams by Staudinger Ketene‐Imine Cycloaddition Reaction
European Journal of Organic Chemistry, 1999Co-Authors: Claudio Palomo, Jesus Mari Aizpurua, I Ganboa, Mikel OiarbideAbstract:[2 + 2] Cycloaddition reactions between ketenes, bearing amino-, oxy-, or halo- groups, and imines are recognized as being amongst the most important and direct routes to β-Lactams. Alkyl-substituted ketenes also furnished the corresponding β-Lactams upon reaction with activated imines (iminoesters). In general, ketenes are generated from the appropriate acid chloride and a tertiary amine. The major or sole product of the cycloaddition is usually the cis-β-Lactam, although a few exceptions showing trans selectivity are known. In this way β-Lactams with a widely varying substitution pattern at the C-3 and C-4 positions of the ring are constructed stereoselectively. The diastereoselection of the cycloaddition process can be controlled with variable success from chiral groups attached to either the ketene or the imine component, or alternatively to both. This method, in turn, has proved to be valuable for the synthesis of precursors of important β-Lactam antibiotics, and new successful applications can be expected in the near future.
Claudio Palomo - One of the best experts on this subject based on the ideXlab platform.
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asymmetric synthesis of β Lactams by staudinger ketene imine cycloaddition reaction
European Journal of Organic Chemistry, 1999Co-Authors: Claudio Palomo, Jesus Mari Aizpurua, I Ganboa, Mikel OiarbideAbstract:[2 + 2] Cycloaddition reactions between ketenes, bearing amino-, oxy-, or halo- groups, and imines are recognized as being amongst the most important and direct routes to β-Lactams. Alkyl-substituted ketenes also furnished the corresponding β-Lactams upon reaction with activated imines (iminoesters). In general, ketenes are generated from the appropriate acid chloride and a tertiary amine. The major or sole product of the cycloaddition is usually the cis-β-Lactam, although a few exceptions showing trans selectivity are known. In this way β-Lactams with a widely varying substitution pattern at the C-3 and C-4 positions of the ring are constructed stereoselectively. The diastereoselection of the cycloaddition process can be controlled with variable success from chiral groups attached to either the ketene or the imine component, or alternatively to both. This method, in turn, has proved to be valuable for the synthesis of precursors of important β-Lactam antibiotics, and new successful applications can be expected in the near future.
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Asymmetric Synthesis of β‐Lactams by Staudinger Ketene‐Imine Cycloaddition Reaction
European Journal of Organic Chemistry, 1999Co-Authors: Claudio Palomo, Jesus Mari Aizpurua, I Ganboa, Mikel OiarbideAbstract:[2 + 2] Cycloaddition reactions between ketenes, bearing amino-, oxy-, or halo- groups, and imines are recognized as being amongst the most important and direct routes to β-Lactams. Alkyl-substituted ketenes also furnished the corresponding β-Lactams upon reaction with activated imines (iminoesters). In general, ketenes are generated from the appropriate acid chloride and a tertiary amine. The major or sole product of the cycloaddition is usually the cis-β-Lactam, although a few exceptions showing trans selectivity are known. In this way β-Lactams with a widely varying substitution pattern at the C-3 and C-4 positions of the ring are constructed stereoselectively. The diastereoselection of the cycloaddition process can be controlled with variable success from chiral groups attached to either the ketene or the imine component, or alternatively to both. This method, in turn, has proved to be valuable for the synthesis of precursors of important β-Lactam antibiotics, and new successful applications can be expected in the near future.
C. Quiniou - One of the best experts on this subject based on the ideXlab platform.
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Insertion of multiple alpha-amino gamma-Lactam (Agl) residues into a peptide sequence by solid-phase synthesis on synphase lanterns.
Biopolymers, 2010Co-Authors: Luisa Ronga, A.g. Jamieson, K. Beauregard, C. Quiniou, S. Chemtob, W.d. LubellAbstract:The insertion of Lactams into peptide analogs can enhance potency and improve receptor selectivity. The synthesis of Lactam-bridged peptide sequences has been accomplished by a solid-phase approach on SynPhase lanterns using cyclic (R)- and (S)-oxathiazinane ester (2) to annulate the amino Lactam residue onto the peptide chain. Parallel synthesis of alpha-amino gamma-Lactam analogs of the allosteric modulator of IL-1 receptor 101.10 (D-Arg-D-Tyr-D-Thr-D-Val-D-Glu-D-Leu-D-Ala: rytvela) was performed by split-mix chemistry on the lanterns. In particular, the double insertion of alpha-amino gamma-Lactams in the same peptide sequence has been accomplished by this effective method for the solid-supported combinatorial synthesis of Lactam-bridged peptides. Peptides bearing an Agl residue exhibited curve shapes indicative of turn conformations in their circular dichroism spectra.
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positional scanning for peptide secondary structure by systematic solid phase synthesis of amino Lactam peptides
Journal of the American Chemical Society, 2009Co-Authors: Andrew G Jamieson, K. Beauregard, C. Quiniou, S. Chemtob, Nicolas Boutard, Mandar S Bodas, W.d. LubellAbstract:Incorporation of amino Lactams into biologically active peptides has been commonly used to restrict conformational mobility, enhance selectivity, and increase potency. A solid-phase method using a Fmoc-protection strategy has been developed for the systematic synthesis of peptides containing configurationally defined α- and β-amino γ-Lactams. N-Alkylation of N-silyl peptides with five- and six-member cyclic sulfamidates 9 and 8 minimized bis-alkylation and provided N-alkyl peptides, which underwent Lactam annulation under microwave heating. Employing this solid-phase protocol on the growth hormone secretagogue GHRP-6, as well as on the allosteric modulator of the IL-1 receptor 101.10, has furnished 16 Lactam derivatives and validated the effectiveness of this approach on peptides bearing aliphatic, aromatic, branched, charged, and heteroatomic side chains. The binding affinity IC50 values of the GHRP-6 Lactam analogues on both the GHS-R1a and CD36 receptors are reported as well as inhibition of thymocyte ...
S. Chemtob - One of the best experts on this subject based on the ideXlab platform.
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Insertion of multiple alpha-amino gamma-Lactam (Agl) residues into a peptide sequence by solid-phase synthesis on synphase lanterns.
Biopolymers, 2010Co-Authors: Luisa Ronga, A.g. Jamieson, K. Beauregard, C. Quiniou, S. Chemtob, W.d. LubellAbstract:The insertion of Lactams into peptide analogs can enhance potency and improve receptor selectivity. The synthesis of Lactam-bridged peptide sequences has been accomplished by a solid-phase approach on SynPhase lanterns using cyclic (R)- and (S)-oxathiazinane ester (2) to annulate the amino Lactam residue onto the peptide chain. Parallel synthesis of alpha-amino gamma-Lactam analogs of the allosteric modulator of IL-1 receptor 101.10 (D-Arg-D-Tyr-D-Thr-D-Val-D-Glu-D-Leu-D-Ala: rytvela) was performed by split-mix chemistry on the lanterns. In particular, the double insertion of alpha-amino gamma-Lactams in the same peptide sequence has been accomplished by this effective method for the solid-supported combinatorial synthesis of Lactam-bridged peptides. Peptides bearing an Agl residue exhibited curve shapes indicative of turn conformations in their circular dichroism spectra.
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positional scanning for peptide secondary structure by systematic solid phase synthesis of amino Lactam peptides
Journal of the American Chemical Society, 2009Co-Authors: Andrew G Jamieson, K. Beauregard, C. Quiniou, S. Chemtob, Nicolas Boutard, Mandar S Bodas, W.d. LubellAbstract:Incorporation of amino Lactams into biologically active peptides has been commonly used to restrict conformational mobility, enhance selectivity, and increase potency. A solid-phase method using a Fmoc-protection strategy has been developed for the systematic synthesis of peptides containing configurationally defined α- and β-amino γ-Lactams. N-Alkylation of N-silyl peptides with five- and six-member cyclic sulfamidates 9 and 8 minimized bis-alkylation and provided N-alkyl peptides, which underwent Lactam annulation under microwave heating. Employing this solid-phase protocol on the growth hormone secretagogue GHRP-6, as well as on the allosteric modulator of the IL-1 receptor 101.10, has furnished 16 Lactam derivatives and validated the effectiveness of this approach on peptides bearing aliphatic, aromatic, branched, charged, and heteroatomic side chains. The binding affinity IC50 values of the GHRP-6 Lactam analogues on both the GHS-R1a and CD36 receptors are reported as well as inhibition of thymocyte ...
