1 / 47

Université René Descartes – Paris 5 UFR Biomédicale des Saints-Pères Ecole Doctorale du Médicament

Université René Descartes – Paris 5 UFR Biomédicale des Saints-Pères Ecole Doctorale du Médicament. Strategic investigations for the design of a library of liposidomycins analogs, natural antibiotics dedicated to the MraY translocase. Maryon GINISTY Direction : Pr. Yves Le Merrer

patsy
Download Presentation

Université René Descartes – Paris 5 UFR Biomédicale des Saints-Pères Ecole Doctorale du Médicament

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Université René Descartes – Paris 5UFR Biomédicale des Saints-PèresEcole Doctorale du Médicament Strategic investigations for the design of a library of liposidomycins analogs, natural antibiotics dedicated to the MraY translocase Maryon GINISTY Direction : Pr. Yves Le Merrer Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques Direction : Dr. Daniel Mansuy - UMR 8601 – CNRS 45, rue des Saints-Pères - 75270 Paris Cedex 06- France

  2. ANTIBACTERIAL RESISTANCE : A MAJOR OBSTACLE FOR ANTIBIOTHERAPY  1940’s : development of penicillin and appearance of the concept of antibiotics « Agents with specific antibacterial action and with toxicity selectively directed against bacteria in low concentrations » ►Bacteriostaticeffect (decrease or stop of bacterial growth) ►Bactericideffect (destruction of bacteria) ● Complexity and adaptability of bacterial world ►Therapeutic failure ►Development of a large number of antibiotics classified according to various criteria : site of action, origin, administation route, structure ⇒ Eight major families: b-lactams, aminosides, macrolides, sulfamides, poly- et glyco-peptides, cyclins, (fluoro)quinolons…

  3. RESISTANT STRAINS AND MECHANISMS ⇒ Resistantstrain : strain able to develop in the presence of an antibiotic concentration notably higher than that which inhibits development of other strains of same species antibiotic antibiotic antibiotic « modifying » enzyme pump ● Two types of resistance : ►Naturalresistance (intrinsic property related to the bacterial genetic program) ► Acquired resistance (property resulting from genetic modifications of the bacterial cells) ● Five major mechanisms of resistance : - Overproduction of antibiotic target - Metabolic bypass of inhibited reaction - Inactivation of antibiotic by enzymatic modification - Modification of target eliminating or reducing antibiotic binding to target X resistance gene receptor modified receptor modified antibiotic - Decrease of cellular permeability to antibiotic

  4. SITES OF ACTION OF ANTIBIOTICS AND POTENTIAL TARGETS ⇒ Four sites of action specific to procaryote bacterial cells - ribosomes responsible for protein synthesis - metabolism of nucleic acids ⇒ inhibition of DNA synthesis ⇒inhibition of DNA transcription into messenger RNA - oxydoreduction (5-nitro-imidazoles) via formation of superoxides and nitro radicalsresponsible of irreversible damage on bacterial DNA - cell wall biosynthesis BACTERIA Bacterial wall mRNA RNA-polymerase mRNA Gram (+) cell lipopolysaccharide external membrane ribosome DNA periplasm cytoplasmic membrane DNA-gyrase aminoacid cytoplasmic membrane peptidoglycan cytoplasm cytoplasm Gram (-) cell

  5. ANTIBIOTICS AND BACTERIAL PEPTIDOGLYCAN BIOSYNTHESIS fosfomycin tunicamycin muraymycin mureidomycin liposidomycin D-cycloserin D-cycloserin P B P s U M P U D P - G l c N A c B a c A M u r G P i U D P P B P s MraY Undecaprenyl-P Lipid I CYTOPLASM MEMBRANE bacitracin Undecaprenyl-PP Lipid II Acceptor Polymer PERIPLASM penicillin cephalosporin moenomycin UDP-MurNAc-pentapeptide vancomycin Peptidoglycan

  6. INHIBITORS AND NATURAL SUBSTRATE OF MraY TRANSLOCASE

  7. STRUCTURE OF LIPOSIDOMYCINS S S S S

  8. SYNTHETIC APPROACHES DESCRIBED IN LITTERATURE  1,4-diazepan-2-one moiety ⇖ ⇖ ⇖ Knapp et coll. Tetrahedron Lett.1992, 33, 5485. Knapp et coll. J. Org. Chem.2001, 66, 5822.

  9. SYNTHETIC APPROACHES DESCRIBED IN LITTERATURE  Ribosyl-diazepanone Isono et coll. Heterocycles1992, 34, 1147.

  10. SYNTHETIC APPROACHES DESCRIBED IN LITTERATURE  Nucleosidyl-diazepanone Knapp et coll. Org. Lett.2002, 4, 603. 1/ Oxidation 2/ NaN3 1/ Ozonolysis 2/ Azide reduction 3/ Reductive amination

  11. SYNTHETIC APPROACHES DESCRIBED IN LITTERATURE  Nucleosidyl-ribosyl-diazepanone Angew. Chem. Int. Ed.2005, 44, 1854.

  12. STRUCTURE-ACTIVITY RELATIONSHIP : DEVELOPMENT OF A NEW PHARMACOPHORE MraY

  13. STRUCTURE-ACTIVITY RELATIONSHIP: DEVELOPMENT OF A NEW PHARMACOPHORE Structure of natural molecules Pharmacophore structure Target scaffold

  14. SCAFFOLD RETROSYNTHESIS PEPTIDE COUPLING N-ALKYLATION ⇒ O-GLYCOSYLATION

  15. STRATEGIES TOWARDS SCAFFOLD SYNTHESIS N-ALKYLATION PEPTIDE COUPLING GLYCOSYLATION N-ALKYLATION GLYCOSYLATION PEPTIDE COUPLING

  16. ACCESS TO THE SCAFFOLD BY « CHAIN EXTENSION »  STEPS AND PRECURSORS STRATEGY 1 ⇗ STRATEGY 2 ⇘ STRATEGY 1

  17. ACCESS TO THE SCAFFOLD BY « CHAIN EXTENSION »  GLYCOSYLATION STEP X= Br, Cl, F X= Br, Cl, F, SR = OCOR, O3SR, OP(OR)2, OPO2-OR'. Substitution via activation of anomeric position R-OH (acceptor) H+ R-OH acceptor Direct acid-catalyzed substitution

  18. ELABORATION OF O-GLYCOSYLATION STEP (1) ⇒ Tricky step : - for the formation of O-glycosidic derivatives, less known than that of N-glycosidic analogs - in the particular case of threonyl and serinyl acceptors Basic lability Acid lability

  19. ELABORATION OF O-GLYCOSYLATION STEP (2) b activator a ⇒ Success of the reaction and control of stereochemistry depending on three principal factors : - nature of glycosylation activator - nature of activation in anomeric position -nature of the C-2 substituent of the ribose controling a- or b-selective introduction of serine (anchimeric assistance)

  20. ACTIVATION IN ANOMERIC POSITION STRATEGY 1 DAST, THF, -30°C to RT, 1h. 95% (b/a = 99/1) X = Cl SOCl2, DCM, 0°C to RT X = Br TMS-Br, DCM, -40°C to RT. R1= Ac R2 = Ac, Bz, Bn R1= H R2 = Bn R1, R2 = H Koenigs-Knorr method STRATEGY 2

  21. FORMATION OF PREFUNCTIONALIZED RIBOFURANOSIDES a: 1/ H2SO4 (0,1N), 65°C, 4h; 2/ Me2C(OMe)2, CSA, Me2CO, 50°C, 30 min. 1/ DOWEX 50W-H+, MeOH, 65°C, 17h. 2/ Ac2O, pyridine, RT, 2h.

  22. SYNTHESIS OF L-SERINYL ACCEPTORS R=Fmoc, Cbz R= Boc, Cbz, Fmoc R=Boc R= Cbz

  23. SELECTION OF ACTIVATORS AND OPTIMIZATION OF GLYCOSYLATION CONDITIONS  Hg(CN)2  AgClO4  TMS-OTf  BF3.OEt2 AgOTf SnCl2/ AgClO4  STRATEGY 1 (riboses not functionalized )  STRATEGIE 2 (prefunctionalizedriboses) X = Br, Cl, F X = Br, Cl, F SnCl2/ AgClO4 Ginisty M., Gravier-Pelletier C., Le Merrer Y., Tetrahedron: Asymmetry 2004, 15, 189-193. Ginisty M., Gravier-Pelletier C., Le Merrer Y., Tetrahedron: Asymmetry 2006, 17, 142-150 .

  24. ACCESS TO THE SCAFFOLD BY « CHAIN EXTENSION » STRATEGY 1 ⇗ STRATEGY 2 STRATEGY 1 ⇘

  25. FUNCTIONALIZATION OF RIBOSYL MOIETY substitution of the 5’-OH function substitution of the 5’-OH function functionalization at C-2’ and C-3’ positions C-2’ and C-3’ protection deprotection P1 = Ac, Bz, Bn P2 = C(CH3)2 R = Z82% Boc - X

  26. ACCESS TO THE SCAFFOLD BY « CHAIN EXTENSION » STRATEGY 1 ⇗ STRATEGY 2 STRATEGY 1 ⇘

  27. AMINE DEPROTECTION  STRATEGY 1 H2, Pd(OH)2/ C, CH3CO2H, EtOH abs., RT, 24h. H2, Pd(OH)2/ C, CH3CO2H, EtOH abs., RT, 48h. H2, Pd black, CH3CO2H, RT, 48h. X R = Ac, Bz  STRATEGY 2 HCO2NH4 Pd/C 10% MeOH, TA. X Y= PhtN-, ZHN-

  28.  Powerful glycosylation conditions for the diastereoselective formation of serinyl-5’-amino-b-D-ribofuranoside derivatives ⇒ unfinished strategy because of difficult functionalization of the ribosyl moiety and amine deprotection. ACCES TO THE SCAFFOLD BY « CHAIN EXTENSION » : CONCLUSION AND PERSPECTIVES • Perspective : ⇒ strategy 2 : glycosylation of 2,3-O-isopropyliden-D-ribofuranoside derivatives differently N-protected, whose synthesis was already carried out. . Y = PhtN-, ZHN- X = activated group

  29. ACCESS TO THE SCAFFOLD BY DIRECT COUPLING H O Y a m i n o - d i h y d r o x y - P O b u t a n e N H 2 N-ALKYLATION PEPTIDE COUPLING GLYCOSYLATION GLYCOSYLATION

  30. ACCESS TO THE SCAFFOLD BY DIRECT COUPLING CAG STRATEGY ACG STRATEGY

  31. FORMATION OF N1-C2 LINKAGE BY PEPTIDE COUPLING- FIRST STEP OF THE CAG STRATEGY -  SYNTHESIS OF AMINO-BUTANOL PRECURSORS 3,4-O-methylethyliden-L-threonine ethyl ester

  32. FORMATION OF N1-C2 LINKAGE BY PEPTIDE COUPLING- FIRST STEP OF THE CAG STRATEGY -  SYNTHESIS OF AMINO-BUTANOL PRECURSORS Introduction of an electrophilic group in C1 position introduction in C3 position of the azido group   180° rotation 180° rotation L-ascorbic acid introduction of the azido group in C2 position introduction of an electrophilic group in C4 position P : protecting group R = OEt, H

  33. FORMATION OF N1-C2 LINKAGE BY PEPTIDE COUPLING- FIRST STEP OF THE CAG STRATEGY -  SYNTHESIS OF AMINO-BUTANOL PRECURSORS

  34. PEPTIDE COUPLING : SUBSTRATES AND PRODUCTS PEPTIDE COUPLING COUPLING PRODUCTS YIELD a 100 % a 100 % a or b * a : PyBOP, DIEA, CH2Cl2 b : HBTU, DIEA, DMF * 25 % of epimerization in C2 position

  35. ACCESS TO THE SCAFFOLD BY DIRECT COUPLING CAG STRATEGY ACG STRATEGY

  36. ACCESS TO THE SCAFFOLD BY DIRECT COUPLING CAG STRATEGY INTRAMOLECULAR PATHWAY ACG STRATEGY INTERMOLECULAR PATHWAY

  37. FORMATION OF N4-C5 LINKAGE BY N-ALKYLATION INTRAMOLECULAR PATHWAY (CAG Strategy) INTERMOLECULAR PATHWAY (ACG Strategy)

  38. FORMATION OF N4-C5 LINKAGE BY N-ALKYLATION : NUCLEOPHILIC ATTACK OF AN ACTIVATED PRIMARY CARBON  INTERMOLECULARPATHWAY

  39. FORMATION OF N4-C5 LINKAGE BY N-ALKYLATION : NUCLEOPHILIC ATTACK OF AN ACTIVATED PRIMARY CARBON  INTRAMOLECULAR PATHWAY piperidine, DMF, RT 65% epoxide opening deprotection X X Acid conditions : Yb(OTf)3, (Et3N), CH2Cl2, RT, 6 days. LiNTf2, CH2Cl2, RT, 48h. Basic conditions : Cs2CO3, DMF, RT to 110°C, 20h. tBuOH, NaH, 100°C. « Neutral » conditions : MeOH, RT, 15 days. iPrOH, RT, 18h. iPrOH, 50°C, 4 days.

  40. MOLECULAR MODELING OF AMINO-EPOXIDE Amine function involved in epoxide ring opening Primary carbon atom of epoxide ring « -stacking » interactions « -stacking » interactions

  41. N-ALKYLATION BY REDUCTIVE AMINATION  SYNTHESIS OF PRECURSORS INVOLVED IN REDUCTIVE AMINATION 1/ Aldehyde derivatives functionalization of the diol moiety reductive amination peptide coupling reductive amination functionalization of the diol moiety P= TBDPS

  42. FUNCTIONALIZATION OF THE DIOL MOIETY N-ALKYLATION BY REDUCTIVE AMINATION R’ = H R’ = TBDPS  SYNTHESIS OF PRECURSORS INVOLVED IN REDUCTIVE AMINATION R = H R = Z 2/ Serinyl derivatives 1/ Step 1 2/ NaBH3CN, EtOH abs., 18 h. reductive amination reductive amination 1/ Step 1 2/ NaBH3CN, EtOH abs., 18 h.

  43. ACCESS TO THE SCAFFOLD BY DIRECT COUPLING CAG STRATEGY ACG STRATEGY

  44. FORMATION OF N1-C2 LINKAGE BY PEPTIDE COUPLING 1 2 azido reduction deprotection X AND deprotection R2 = H peptide coupling X

  45. MOLECULAR MODELING OF THE « COMPLEX AMINO-ACIDS » -stacking interaction -stacking interaction -stacking interaction « hydrophobic site  » bis-O-silylated compound amine function involved in peptide coupling acid function involved in peptide coupling hydrophobic interactions Mono-O-silylated compound

  46. CONCLUSION AND PERSPECTIVES ⇒ RING CLOSURE ? ⇒ HOAt N-ALKYLATION 5 4 6 3 X 7 O-GLYCOSYLATION 2 1 PEPTIDE COUPLING

  47. TOWARDS A NEW FAMILY OF POTENTIAL ANTIBIOTICS N-Alkylation of L-serine tert-butyl ester + Intramolecular peptide Coupling +O-Glycosylation of diazepanone heterocycle Ribosyl-diazepanone scaffold + R1/ R2/ R3 Family of powerful MraY inhibitors ⇒ Biologic evaluation (Laboratoire des Enveloppes Bactériennes et Antibiotiques – Dr D. Blanot – Dr. D. Mengin-Lecreulx)

More Related