Category: L.T.Maillard_publications

Can Heterocyclic γ-Peptides Provide Polyfunctional Platforms for Synthetic Glycocluster Construction?

Chemistry. 2018 May 30. doi: 10.1002/chem.201802032

Simon M, Ali LMA, El Cheikh K, Aguesseau J, Gary-Bobo M, Garcia M, Morère A, Maillard LT.

Abstract

Sugars play key roles in many molecular and cellular communication processes involving a family of proteins named lectins. The low affinity associated with sugar recognition is generally counterbalanced by the multivalent nature of the interaction. While many polyglycosylated architectures have been described, only a few studies focused on the impact of topology variations of the multivalent structures on the interaction with lectin proteins. One major interest of our group concerns the design of new highly predictable and stable molecular pseudo‐peptide architectures for therapeutic applications. In such a context, we described a class of constrained heterocyclic γ‐amino acids built around a thiazole ring, named ATCs. ATC oligomers are helical molecules resulting from the formation of a highly stable C9 hydrogen‐bonding pattern. Following our program, we herein address the potential of ATC oligomers as tunable scaffolds for the development of original multivalent glycoclusters.

C9/12 Ribbon-Like Structures in Hybrid Peptides Alternating α- and Thiazole-Based γ-Amino Acids

Chemistry. 2017 Dec 11;23(69):17584-17591. doi: 10.1002/chem.201704001. Epub 2017 Nov 15.

Bonnel C, Legrand B, Simon M, Martinez J, Bantignies JL, Kang YK, Wenger E, Hoh F, Masurier N, Maillard LT.

Abstract

According to their restricted conformational freedom, heterocyclic γ-amino acids are usually considered to be related to Z-vinylogous γ-amino acids. In this context, oligomers alternating α-amino acids and thiazole-based γ-amino acids (ATCs) were expected to fold into a canonical 12-helical shape as described for α/γ-hybrid peptides composed of cis-α/β-unsaturated γ-amino acids. However, through a combination of X-ray crystallography, NMR spectroscopy, FTIR experiments, and DFT calculations, it was determined that the folding behavior of ATC-containing hybrid peptides is much more complex. The homochiral α/(S)-ATC sequences were unable to adopt a stable conformation, whereas the heterochiral α/(R)-ATC peptides displayed novel ribbon structures stabilized by unusual C9/12 -bifurcated hydrogen bonds. These ribbon structures could be considered as a succession of pre-organized γ/α dipeptides and may provide the basis for designing original α-helix mimics.

1,2,4-Triazole-3-thione Compounds as Inhibitors of Dizinc Metallo-β-lactamases

ChemMedChem 2017 Jun 21;12(12):972-985. doi: 10.1002/cmdc.201700186. Epub 2017 Jun 12.

Sevaille L, Gavara L, Bebrone C, De Luca F, Nauton L, Achard M, Mercuri P, Tanfoni S, Borgianni L, Guyon C, Lonjon P, Turan-Zitouni G, Dzieciolowski J, Becker K, Bénard L, Condon C, Maillard L, Martinez J, Frère JM, Dideberg O, Galleni M, Docquier JD, Hernandez JF.

Abstract

Metallo-β-lactamases (MBLs) cause resistance of Gram-negative bacteria to β-lactam antibiotics and are of serious concern, because they can inactivate the last-resort carbapenems and because MBL inhibitors of clinical value are still lacking. We previously identified the original binding mode of 4-amino-2,4-dihydro-5-(2-methylphenyl)-3H-1,2,4-triazole-3-thione (compound IIIA) within the dizinc active site of the L1 MBL. Herein we present the crystallographic structure of a complex of L1 with the corresponding non-amino compound IIIB (1,2-dihydro-5-(2-methylphenyl)-3H-1,2,4-triazole-3-thione). Unexpectedly, the binding mode of IIIB was similar but reverse to that of IIIA. The 3 D structures suggested that the triazole-thione scaffold was suitable to bind to the catalytic site of dizinc metalloenzymes. On the basis of these results, we synthesized 54 analogues of IIIA or IIIB. Nineteen showed IC50 values in the micromolar range toward at least one of five representative MBLs (i.e., L1, VIM-4, VIM-2, NDM-1, and IMP-1). Five of these exhibited a significant inhibition of at least four enzymes, including NDM-1, VIM-2, and IMP-1. Active compounds mainly featured either halogen or bulky bicyclic aryl substituents. Finally, some compounds were also tested on several microbial dinuclear zinc-dependent hydrolases belonging to the MBL-fold superfamily (i.e., endonucleases and glyoxalase II) to explore their activity toward structurally similar but functionally distinct enzymes. Whereas the bacterial tRNases were not inhibited, the best IC50 values toward plasmodial glyoxalase II were in the 10 μm range.

FT-IR and NMR structural markers for thiazole-based γ-peptide foldamers

Organic & Biomolecular Chemistry, 2016, Volume: 14, Issue: 37, Pages: 8664-8669, DOI: 10.1039/C6OB01594H

C. Bonnel, B. Legrand, J. L. Bantignies, H. Petitjean, J. Martinez, N. Masurier, L. T. Maillard 

Abstract

In the search of new robust and environmental-friendly anal. methods able to answer quant. issues in pharmacol., we explore liq. chromatog. (LC) assocd. with elemental mass spectrometry (ICP-MS) to monitor peptides in such complex biol. matrixes.  The novelty is to use mass spectrometry to replace radiolabelling and radioactivity measurements, which represent up-to now the gold std. to measure org. compd. concns. in life science.  As a proof of concept, we choose the vasopressin (AVP)/V1A receptor system for model pharmacol. assays.  The capacity of ICP-MS to provide highly sensitive quantitation of metallic and hetero elements, whatever the sample medium, prompted us to investigate this technique in combination with appropriate labeling of the peptide of interest.  Selenium, that is scarcely present in biol. media, was selected as a good compromise between ICP-MS response, covalent tagging ability using conventional sulfur chem. and peptide detection specificity.  Applying selenium monitoring by elemental mass spectrometry in pharmacol. is challenging due to the very high salt content and org. material complexity of the samples that produces polyat. aggregates and thus potentially mass interferences with selenium detection.  Hyphenation with a chromatog. sepn. was found compulsory.  Noteworthy, we aimed to develop a straightforward quant. protocol that can be performed in any lab. equipped with a std. macrobore LC-ICP-MS system, in order to avoid time-consuming sample treatment or special implementation of instrumental set-up, while allowing efficient suppression of all mass interferences to reach the targeted sensitivity.  Significantly, a quantification limit of 57 ng Se L-1 (72 fmol of injected Se) was achieved, the samples issued from the pharmacol. assays being directly introduced into the LC-ICP-MS system.  The established method was successfully validated and applied to the measurement of the vasopressin ligand affinity for its V1A receptor through the detn. of the dissocn. const. (Kd) which was compared to the one recorded with conventional radioactivity assays.

Imidazopyridine-fused [1,3]-diazepinones part 2: Structure-activity relationships and antiproliferative activity against melanoma cells

European Journal of Medicinal Chemistry, 2016, Volume: 125, Pages: 1225-1234, DOI: 10.1016/j.ejmech.2016.11.023

V. Bellet, L. Lichon, D. P. Arama, A. Gallud,  V. Lisowski, L. T. Maillard, M. Garcia, J. Martinez, N. Masurier

Diapositive 1

Abstract

We recently described a pyrido-imidazodiazepinone deriv. which could be a promising hit compd. for the development of new drugs acting against melanoma cells. In this study, a series of 28 novel pyrido-imidazodiazepinones were synthesized and screened for their in vitro cytotoxic activities against the melanoma MDA-MB-435 cell line. Among the derivs., seven of them showed 50% growth inhibitory activity at 1 μM concn., and high selectivity against the melanoma cell line MDA-MB-435.

Pyrido-imidazodiazepinones as a new class of reversible inhibitors of human kallikrein 7

European Journal of Medicinal Chemistry, 2015, Volume: 93, Pages: 202-213, DOI: 10.1016/j.ejmech.2015.02.008

D. P. Arama, F. Soualmia, V. Lisowski, J.-F. Longevial, E. Bosc, L. T. Maillard, J. Martinez, N. Masurier, C. El Amri

Abstract

The human tissue kallikrein-7 (KLK7) is a chymotryptic serine protease member of tissue kallikrein family.  KLK7 is involved in skin homeostasis and inflammation.  Excess of KLK7 activity is also assocd. with tumor metastasis processes, esp. in ovarian carcinomas, prostatic and pancreatic cancers.  Development of Kallikrein 7 inhibitors is thus of great interest in oncol. but also for treating skin diseases.  Most of the developed synthetic inhibitors present several drawbacks such as poor selectivity and unsuitable physico-chem. properties for in vivo use.  Recently, the authors described a practical sequence for the synthesis of imidazopyridine-fused [1,3]-diazepines.  Here, the authors report the identification of pyrido-imidazodiazepinone core as a new potential scaffold to develop selective and competitive inhibitors of kallikrein-related peptidase 7.  Structure-activity relationships (SAR), inhibition mechanisms and selectivity as well as cytotoxicity against selected cancer cell lines were investigated.

Cross-Claisen condensation of N-Fmoc-amino acids – a short route to heterocyclic γ-amino acids

European Journal of Organic Chemistry, 2015, Volume: 2015, Issue: 10, Pages: 2262-2270, DOI: 10.1002/ejoc.201500012

L. Mathieu, C. Bonnel, N. Masurier, L. T. Maillard, J. Martinez, V. Lisowski

Abstract

4-Amino(methyl)-1,3-thiazole-5-carboxylic acids (ATCs) are a new class of constrained heterocyclic γ-amino acids built around a thiazole ring; these compds. are valuable as design mimics of the secondary structures of proteins such as helixes, β-sheets, turns, and β-hairpins.  We report herein a short and versatile chem. route to orthogonally protected ATCs.  The synthesis is centered on cross-Claisen condensations between N-Fmoc-amino acids and sterically hindered 1,1-dimethylallyl acetate.  The optimized conditions are compatible with aliph., arom., acidic, and basic amino acids.  The resulting N-Fmoc-β-keto ester intermediates were engaged in a two-step process to give ATCs in 45-90 % yields.  The synthetic protocol provides a highly flexible method for the introduction of a wide variety of lateral chains either on the γ-carbon atom or on the thiazole core of the γ-amino acids.

Synthesis of Thieno[3,2-e][1,4]diazepin-2-ones: Application of an Uncatalysed Pictet-Spengler Reaction

European Journal of Organic Chemistry, 2015, Volume: 2015, Issue: 32, Pages: 7146-7153, DOI: 10.1002/ejoc.201500943

S. Denoyelle, G. Tambutet, N. Masurier, L. T. Maillard, J. Martinez, V. Lisowski

Abstract

A series of 5-substituted thieno[3,2-e][1,4]diazepin-2-ones was synthesized in four steps from Me 3-aminothiophene-2-carboxylate.  After the coupling of 3-aminothiophene with α-amino acids, the key final step that involves an uncatalyzed Pictet-Spengler reaction allowed the cyclization of the seven-membered diazepinone ring.  The reaction was first optimized and then exemplified in three different series (phenylalanine, alanine and proline) that led to 24 target diazepinones, which includes 19 optically pure diastereomers.

Imidazopyridine-fused [1,3]-diazepinones: Synthesis and antiproliferative activity

European Journal of Medicinal Chemistry, 2014, Volume: 75, Pages: 382-390,  DOI: 10.1016/j.ejmech.2014.01.044

A. Gallud, O. Vaillant, L.T. Maillard, D. Arama, J. Dubois, M. Maynadier, V. Lisowski, M. Garcia, J. Martinez, N. Masurier

Abstract

A series of 15 pyrido-imidazo-1,3-diazepin-5-ones and pyrido-1,3-diazepine-2,5-diones were synthesized and their anticancer activities were evaluated.  Among tested compds. on a cell lines panel, compd. I presents the best growth inhibition activity on 21 cell lines with a cytotoxic effect on MDA-MB-435 melanoma cells.  This compd. led to deep cell morphol. changes and revealed to be an inhibitor of the Hepatocyte progenitor kinase-like kinase (HGK), which is known to be implicated in the migration, adhesion and invasion of various tumor cells.

Synthesis and reactivity of pyrrolo[3,2-d][1,3]oxazine-2,4-dione. Access to new pyrrolo[3,2-e][1,4]diazepine-2,5-diones

Tetrahedron, 2014, Volume: 70, Issue: 31, Pages: 4631-4639, DOI: 10.1016/j.tet.2014.05.046

J. Malcor, Y. Brouillette, J. Graffion, K. Spielmann, N. Masurier, L. T. Maillard, J. Martinez, V. Lisowski

Abstract

A convenient synthesis of pyrrolo[3,2-d][1,3]oxazine-2,4-dione is described and its reactivity towards various nucleophiles studied.  The regioselective ring opening of pyrrolo[3,2-d][1,3]oxazine-2,4-dione or its N-alkylated analog in the presence of alanine or proline afforded, resp., imidazolidinedione and 2 N-protected pyrrolo[3,2-e][1,4]diazepines in a one-pot process.  In a last part of this study, an alternative route to produce a library of eight non protected pyrrolo[3,2-e][1,4]diazepine-2,5-diones is described to overcome the limited reactivity of pyrrolo[3,2-d][1,3]oxazine-2,4-dione.