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Design of Triazolium-Grafted Peptidomimetic Macrocycles with Facial Amphipathicity to Target Pathogenic Bacteria. Org Lett 2024; 26:4088-4092. [PMID: 38709636 DOI: 10.1021/acs.orglett.4c01149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Access to 1,2,3-triazolium-grafted peptoid macrocycles was developed by macrocyclization and multivalent postmodification of linear peptoid oligomers carrying an alternance of benzylic and propargyl groups as side chains. X-ray analysis and NMR studies revealed a conformational preference for constrained hairpin-shaped structures leading to the facial amphipathic character of these macrocycles. A preliminary evaluation showed the antimicrobial activities of these new cationic amphipathic architectures.
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2
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Unveiling the conformational landscape of achiral all- cis tert-butyl β-peptoids. Org Biomol Chem 2022; 20:7907-7915. [PMID: 36173021 DOI: 10.1039/d2ob01351g] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis and conformational study of N-substituted β-alanines with tert-butyl side chains is described. The oligomers prepared by submonomer synthesis and block coupling methods are up to 15 residues long and are characterised by amide bonds in the cis-conformation. A conformational study comprising experimental solution NMR spectroscopy, X-ray crystallography and molecular modeling shows that despite their intrinsic higher conformational flexibility compared to their α-peptoid counterparts, this family of achiral oligomers adopt preferred secondary structures including a helical conformation close to that described with (1-naphthyl)ethyl side chains but also a novel ribbon-like conformation.
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First series of N-alkylamino peptoid homooligomers: solution phase synthesis and conformational investigation. Beilstein J Org Chem 2022; 18:845-854. [PMID: 35923157 PMCID: PMC9296984 DOI: 10.3762/bjoc.18.85] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/29/2022] [Indexed: 11/26/2022] Open
Abstract
The synthesis and conformational analysis of the first series of peptoid oligomers composed of consecutive N-(alkylamino)glycine units is investigated. We demonstrate that N-(methylamino)glycine homooligomers can be readily synthesized in solution using N-Boc-N-methylhydrazine as a peptoid submonomer and stepwise or segment coupling methodologies. Their structures were analyzed in solution by 1D and 2D NMR, in the solid state by X-ray crystallography (dimer 2), and implicit solvent QM geometry optimizations. N-(Methylamino)peptoids were found to preferentially adopt trans amide bonds with the side chain N–H bonds oriented approximately perpendicular to the amide plane. This orientation is conducive to local backbone stabilization through intra-residue hydrogen bonds but also to intermolecular associations. The high capacity of N-(methylamino)peptoids to establish intermolecular hydrogen bonds was notably deduced from pronounced concentration-dependent N–H chemical shift variation in 1H NMR and the antiparallel arrangement of mirror image molecules held together via two hydrogen bonds in the crystal lattice of dimer 2.
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4
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Solution‐Phase Synthesis of Backbone‐Constrained Cationic Peptoid Hexamers with Antibacterial and Anti‐Biofilm Activities. European J Org Chem 2021. [DOI: 10.1002/ejoc.202101155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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5
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Strengthening Peptoid Helicity through Sequence Site-Specific Positioning of Amide cis-Inducing NtBu Monomers. J Org Chem 2020; 85:2190-2201. [PMID: 31873018 DOI: 10.1021/acs.joc.9b02916] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The synthesis of biomimetic helical secondary structures is sought after for the construction of innovative nanomaterials and applications in medicinal chemistry such as the development of protein-protein interaction modulators. Peptoids, a sequence-defined family of oligomers, enable a peptidomimetic strategy, especially considering the easily accessible monomer diversity and peptoid helical folding propensity. However, cis-trans isomerization of the backbone tertiary amides may impair the peptoid's adoption of stable secondary structures, notably the all-cis polyproline I-like helical conformation. Here, we show that cis-inducing NtBu achiral monomers strategically positioned within chiral sequences may reinforce the degree of peptoid helicity, although with a reduced content of chiral side chains. The design principles presented here will undoubtedly help achieve more conformationally stable helical peptoids with desired functions.
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NCα-gem-dimethylated peptoid side chains: A novel approach for structural control and peptide sequence mimetics. Biopolymers 2019; 110:e23273. [PMID: 30897209 DOI: 10.1002/bip.23273] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 01/05/2023]
Abstract
The design of linear peptoid oligomers adopting well-defined secondary structures while mimicking defined peptide primary sequences is a major challenge in the context of drug discovery. To this end, chemists have developed cis-inducing peptoid side chains to build robust polyproline type I helices. However, the number of efficient examples remains scarce and chemical diversity accessible through the use of these side chains is limited. Herein, we introduce an array of NCα-gem-dimethylated peptoid residues mimicking proteinogenic amino acids. Submonomer synthesis and block-coupling approaches were explored to access heterooligomers incorporating these novel types of side chains. NMR studies of monomer and trimer models showed that the NCα-gem-dimethylated groups exert complete cis control on the backbone amide conformation. Lastly, a preliminary molecular modeling study gave an insight into the preferred orientation of the substituents of the NCα-gem-dimethyl side chains relative to the peptoid backbone.
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Design, Synthesis, and Immunological Evaluation of a Multicomponent Construct Based on a Glycotripeptoid Core Comprising B and T Cell Epitopes and a Toll-like Receptor 7 Agonist That Elicits Potent Immune Responses. J Med Chem 2018; 61:9568-9582. [PMID: 30351939 DOI: 10.1021/acs.jmedchem.8b00960] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We present here for the first time the synthesis and immunological evaluation of a fully synthetic three-component anticancer vaccine candidate that consists of a β-glycotripeptoid core mimicking a cluster of Tn at the surface of tumor cells (B epitope), conjugated to the OVA 323-339 peptide (T-cell epitope) and a Toll-like receptor 7 (TLR7) agonist for potent adjuvanticity. The immunological evaluation of this construct and of precursor components demonstrated the synergistic activity of the components within the conjugate to stimulate innate and adaptive immune cells (DCs, T-helper, and B-cells). Surprisingly, immunization of mice with the tricomponent GalNAc-based construct elicited a low level of anti-Tn IgG but elicited a very high level of antibodies that recognize the TLR7 agonist. This finding could represent a potential vaccine therapeutic approach for the treatment of some autoimmune diseases such as lupus.
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1,2,3‐Triazolium‐Based Cationic Amphipathic Peptoid Oligomers Mimicking Antimicrobial Helical Peptides. ChemMedChem 2018; 13:1513-1516. [DOI: 10.1002/cmdc.201800273] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/05/2018] [Indexed: 11/06/2022]
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9
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Exploring the Conformation of Mixed Cis–Trans α,β-Oligopeptoids: A Joint Experimental and Computational Study. J Org Chem 2018; 83:6382-6396. [DOI: 10.1021/acs.joc.8b00606] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Homogeneous and Robust Polyproline Type I Helices from Peptoids with Nonaromatic α-Chiral Side Chains. J Am Chem Soc 2017; 139:13533-13540. [PMID: 28837348 DOI: 10.1021/jacs.7b07475] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peptoids that are oligomers of N-substituted glycines represent a class of peptide mimics with great potential in areas ranging from medicinal chemistry to biomaterial science. Controlling the equilibria between the cis and trans conformations of their backbone amides is the major hurdle to overcome for the construction of discrete folded structures, particularly for the development of all-cis polyproline type I (PPI) helices, as tools for modulating biological functions. The prominent role of backbone to side chain electronic interactions (n → π*) and side chains bulkiness in promoting cis-amides was essentially investigated with peptoid aromatic side chains, among which the chiral 1-naphthylethyl (1npe) group yielded the best results. We have explored for the first time the possibility to achieve similar performances with a sterically hindered α-chiral aliphatic side chain. Herein, we report on the synthesis and detailed conformational analysis of a series of (S)-N-(1-tert-butylethyl)glycine (Ns1tbe) peptoid homo-oligomers. The X-ray crystal structure of an Ns1tbe pentamer revealed an all-cis PPI helix, and the CD curves of the Ns1tbe oligomers also resemble those of PPI peptide helices. Interestingly, the CD data reported here are the first for any conformationally homogeneous helical peptoids containing only α-chiral aliphatic side chains. Finally we also synthesized and analyzed two mixed oligomers composed of NtBu and Ns1tbe monomers. Strikingly, the solid state structure of the mixed oligomer Ac-(tBu)2-(s1tbe)4-(tBu)2-COOtBu, the longest to be solved for any linear peptoid, revealed a PPI helix of great regularity despite the presence of only 50% of chiral side chain in the sequence.
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Abstract
The cis-directing effect of the 1,2,3-triazolium-type side chain was studied on dimeric peptoid models with various patterns: αα, αβ, βα and ββ. Low influences of the sequence and of the solvent were observed, the cis conformation of the amide carrying the triazolium ranging from 83 to 94% in proportion. The synthesis of peptoid homooligomers with four or eight pendant 1,2,3-triazolium side chains is described. α-, β- and α,β-peptoids carrying propargyl groups were subjected to CuAAC reaction using alkyl azides, and the resulting triazoles were quaternized providing well-defined multitriazolium platforms. The influence of the counteranion (PF6-, BF4- or I-) on the conformation was also studied.
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12
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Selective complexation of divalent cations by a cyclic α,β-peptoid hexamer: a spectroscopic and computational study. Org Biomol Chem 2016; 14:11371-11380. [DOI: 10.1039/c6ob01954d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The first report on metal binding ability of a cyclic α,β-peptoid hexamer towards a selection of metal cations is presented.
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13
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Correction: Weak backbone CH⋯OC and side chain tBu⋯tBu London interactions help promote helix folding of achiral NtBu peptoids. Chem Commun (Camb) 2016; 52:6625. [DOI: 10.1039/c6cc90163h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Correction for ‘Weak backbone CH⋯OC and side chain tBu⋯tBu London interactions help promote helix folding of achiral NtBu peptoids’ by G. Angelici et al., Chem. Commun., 2016, 52, 4573–4576.
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14
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Weak backbone CH⋯OC and side chain tBu⋯tBu London interactions help promote helix folding of achiral NtBu peptoids. Chem Commun (Camb) 2016; 52:4573-6. [DOI: 10.1039/c6cc00375c] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The synthesis and helix folding propensity of achiral all-cis amide (NtBu)-glycine oligomers is reported.
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15
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Immobilization of proteases on chitosan for the development of films with anti-biofilm properties. Int J Biol Macromol 2015; 72:1063-8. [DOI: 10.1016/j.ijbiomac.2014.09.061] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/16/2014] [Accepted: 09/27/2014] [Indexed: 01/06/2023]
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16
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Multivalent thioglycopeptoids via photoclick chemistry: potent affinities towards LecA and BC2L-A lectins. Chem Commun (Camb) 2015; 51:12301-4. [DOI: 10.1039/c5cc04646g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The straightforward access to peptoid-based multivalent thioglycoclusters displaying 1-thio-β-d-galactose or 1-thio-α/β-d-mannose and their evaluation towards two bacterial lectins are described.
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17
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Rapid and convenient semi-automated microwave-assisted solid-phase synthesis of arylopeptoids. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.08.119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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18
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Effect of proteases against biofilms of Staphylococcus aureus and Staphylococcus epidermidis. Lett Appl Microbiol 2014; 59:507-13. [PMID: 25041576 DOI: 10.1111/lam.12305] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 05/27/2014] [Accepted: 07/07/2014] [Indexed: 01/15/2023]
Abstract
UNLABELLED Biofilms play a key role in bacterial resistance against antibacterial agents-an issue that causes multiple problems in medical fields, particularly with Staphylococcus biofilms that colonize medical indwelling devices. The literature reports several anti-biofilm strategies that have been applied in medicine. Disrupting the biofilm formation process creates new sites open to colonization by treatment-generated planktonic bacteria, so efforts have turned to focus on strategies to prevent and control the initial Staphylococci adhesion. Here, we investigated the preventive activities of three commercial proteases (Flavourzyme, Neutrase and Alcalase) against biofilm formation by two Staphylococcus strains. Some proteolytic extracts revealed interesting results with Staphylococcus epidermidis and Staphylococcus aureus aureus biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY Three proteases were tested against Staphylococcus aureus and Staphylococcus epidermidis biofilms in standard conditions. The Flavourzyme containing a mix of Aspergillus orizae endo- and exoproteases demonstrated significant efficacy against Staph. epidermidis biofilm formation. These results could prove valuable in the effort to develop simple anti-biofilm methods.
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20
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Macrocyclic arylopeptoids – a novel type of cyclic N-alkylated aromatic oligoamides forming nanotubular assemblies. Chem Commun (Camb) 2014; 50:3564-7. [DOI: 10.1039/c4cc00821a] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The head-to-tail macrocyclisation of arylopeptoids (oligomeric N-substituted aminomethyl benzamides) has enabled the first X-ray structures of arylopeptoid constructs and the identification of well-defined architectures in solution.
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21
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Cyclic α,β-tetrapeptoids: sequence-dependent cyclization and conformational preference. Org Lett 2013; 15:3626-9. [PMID: 23806006 DOI: 10.1021/ol401478j] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The presence of at least one N-Cα branched side chain is crucial for successful cyclization of α,β-tetrapeptoids. The ctct amide sequence revealed in the crystal structure of the 14-membered cyclotetrapeptoid 8 is also the most populated conformation in solution and is reminiscent of the predominant amide arrangement of the 12-membered cyclic tetrapeptides (CTPs).
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22
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The tert-Butyl Side Chain: A Powerful Means to Lock Peptoid Amide Bonds in the Cis Conformation. Org Lett 2013; 15:2246-9. [DOI: 10.1021/ol400820y] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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23
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24
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Improved solid-phase synthesis and study of arylopeptoids with conformation-directing side chains. Tetrahedron 2012. [DOI: 10.1016/j.tet.2011.12.049] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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The Click Triazolium Peptoid Side Chain: A Strong cis-Amide Inducer Enabling Chemical Diversity. J Am Chem Soc 2012; 134:9553-6. [DOI: 10.1021/ja302342h] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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27
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Effect of capping groups at the N- and C-termini on the conformational preference of α,β-peptoids. Org Biomol Chem 2012; 10:1108-22. [DOI: 10.1039/c1ob06386c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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28
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Synthesis and binding affinities for sst receptors of cyclic peptoid SRIF-mimetics. MEDCHEMCOMM 2012. [DOI: 10.1039/c2md20265d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Synthesis of the first all-peptoid SRIF (Somatotropin Release-Inhibiting Factor) analogues and evaluation of their binding affinities for the five human somatostatin receptors (hsst1–5).
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29
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Cyclic α,β-peptoid octamers with differing side chain patterns: synthesis and conformational investigation. Amino Acids 2011; 41:663-72. [DOI: 10.1007/s00726-011-0887-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Accepted: 03/08/2011] [Indexed: 11/28/2022]
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30
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Selectivity among two lectins: probing the effect of topology, multivalency and flexibility of "clicked" multivalent glycoclusters. Chemistry 2011; 17:2146-59. [PMID: 21294181 DOI: 10.1002/chem.201002635] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Indexed: 11/07/2022]
Abstract
The design of multivalent glycoconjugates has been developed over the past decades to obtain high-affinity ligands for lectin receptors. While multivalency frequently increases the affinity of a ligand for its lectin through the so-called "glycoside cluster effect", the binding profiles towards different lectins have been much less investigated. We have designed a series of multivalent galactosylated glycoconjugates and studied their binding properties towards two lectins, from plant and bacterial origins, to determine their potential selectivity. The synthesis was achieved through copper(I)-catalysed azide-alkyne cycloaddition (CuAAC) under microwave activation between propargylated multivalent scaffolds and an azido-functionalised carbohydrate derivative. The interactions of two galactose-binding lectins from Pseudomonas aeruginosa (PA-IL) and Erythrina cristagalli (ECA) with the synthesized glycoclusters were studied by hemagglutination inhibition assays (HIA), surface plasmon resonance (SPR) and isothermal titration microcalorimetry (ITC). The results obtained illustrate the influence of the scaffold's geometry on the affinity towards the lectin and also on the relative potency in comparison with a monovalent galactoside reference probe.
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31
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Efficient and versatile COMU-mediated solid-phase submonomer synthesis of arylopeptoids (oligomeric N-substituted aminomethyl benzamides). Org Biomol Chem 2011; 9:6832-43. [DOI: 10.1039/c1ob05729d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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32
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Highly Convenient Gram-Scale Solution-Phase Peptoid Synthesis and Orthogonal Side-Chain Post-Modification. SYNTHESIS-STUTTGART 2010. [DOI: 10.1055/s-0030-1258351] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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33
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Click glycoconjugation of per-azido- and alkynyl-functionalized β-peptides built from aspartic acid. Org Biomol Chem 2010; 8:2941-55. [DOI: 10.1039/b923275c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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34
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An Efficient Route to Acyclic C-Nucleosides and Fused-Ring Analogues of Uridine from exo-Glycals. J Org Chem 2009; 74:8388-91. [DOI: 10.1021/jo901604w] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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35
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Synthesis and Solution Conformation of Homo-β-peptides Consisting of N-Mannofuranosyl-3-ulosonic acids. J Org Chem 2009; 74:7651-9. [DOI: 10.1021/jo900966b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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36
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Convenient Solution-Phase Synthesis and Conformational Studies of Novel Linear and Cyclic α,β-Alternating Peptoids. Org Lett 2009; 11:4100-3. [DOI: 10.1021/ol9015767] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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38
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39
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41
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Anomeric spiroannelated 1,4-diazepine 2,5-diones from furano exo-glycals: towards a new class of spironucleosides. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.01.030] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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42
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43
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Facile synthesis of fused furanosyl β-amino acids from protected sugar lactones: incorporation into a peptide chain. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0957-4166(02)00473-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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44
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cis- and trans-3-Azido-oxetane-2-carboxylate scaffolds: hexamers of oxetane cis-β-amino acids. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)00660-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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46
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47
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1,6-anhydro-2, 3-di-O-benzyl-5C-[(R)-ethoxycarbonyl(hydroxy)methyl]-beta-L-altrofur ano se. Acta Crystallogr C 2000; 56 ( Pt 9):1168-9. [PMID: 10986521 DOI: 10.1107/s0108270100008702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2000] [Accepted: 06/20/2000] [Indexed: 11/10/2022] Open
Abstract
The crystal structure of the title compound, C(24)H(28)O(8), has been determined. The conformation of the furanose ring can be described as 58% ideal envelope (O)E conformer and 42% ideal twisted (O)T(1) conformer. The 1,3-dioxane ring adopts a chair conformation with the anhydro-O atom pointing upwards. Both phenyl rings are quasi-perpendicular to the mean plane of the furanose ring. The hydrogen bonding is intermolecular and consists of infinite chains parallel to the a axis.
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48
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Enantiomerically pure decalinic structures from carbohydrates using intramolecular Diels-Alder and Ferrier carbocyclization. CAN J CHEM 2000. [DOI: 10.1139/v00-057] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The synthesis of enantiomerically pure decalinic structures, advanced intermediates for the synthesis of the hexahydronaphtalen part of mevinic acids, is described. The key steps are the intramolecular Diels-Alder cycloaddition of a suitably substituted sugar enone obtained via the Ferrier rearrangement of tri-O-acetyl-D-glucal with the appropriate alcohol representing the diene part of the system. Chemical manipulation of the resulting, diastereomerically pure, cycloadduct led to a 5,6-unsaturated carbohydrate which was submitted to the Ferrier carbocylization. This reaction proved difficult likely because of the embedding of the aglycon in a cycle, the hydration product of the double bond being the main product. This compound was in turn transformed into the decalinic structures by treatment in basic medium. The inverse strategy, Ferrier carbocyclization followed by IMDA of an enone and a diene linked via an ester bond was unsuccessful.Key words: Intramolecular Diels-Alder reaction, enantiomerically pure decalin, Ferrier carbocyclization, carbohydrates.
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49
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Efficient conditions for the synthesis of C-glycosylidene derivatives: a direct and stereoselective route to C-glycosyl compounds. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0957-4166(99)00586-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Synthesis and biological testings as inhibitors of HMGCoA reductase of the seco-acid of tuckolide and its C-7 epimer. Bioorg Med Chem 1999; 7:1049-57. [PMID: 10428373 DOI: 10.1016/s0968-0896(99)00020-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The seco-acid of the natural macrolactone, tuckolide (decarestrictin D) and the C-7 epimer have been prepared in enantiomerically pure form from D-gluconolactone and poly(3-hydroxy butyric acid). The key steps are Horner Emmons olefination and stereoselective reduction of the resulting enone to provide both epimers at C-7. None of the seco-acids inhibit microsomal HMGCoA reductase of pea or rat liver. It may be concluded that the cholesterol biosynthesis inhibiting effect of tuckolide is unlikely to proceed via HMGCoA reductase inhibition.
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