3401-36-3Relevant articles and documents
Ynamide-Mediated Thiopeptide Synthesis
Yang, Jinhua,Wang, Changliu,Xu, Silin,Zhao, Junfeng
supporting information, p. 1382 - 1386 (2019/01/08)
Exploration of the full potential of thioamide substitution as a tool in the chemical biology of peptides and proteins has been hampered by insufficient synthetic strategies for the site-specific introduction of a thioamide bond into a peptide backbone. A novel ynamide-mediated two-step strategy for thiopeptide bond formation with readily available monothiocarboxylic acids as thioacyl donors is described. The α-thioacyloxyenamide intermediates formed from the ynamides and monothiocarboxylic acids can be purified, characterized, and stored. The balance between their activity and stability enables them to act as effective thioacylating reagents to afford thiopeptide bonds under mild reaction conditions. Amino acid functional groups such as OH, CONH2, and indole NH groups need not be protected during thiopeptide synthesis. The modular nature of this strategy enables the site-specific incorporation of a thioamide bond into peptide backbones in both solution and the solid phase.
Mechanistic implications of the enantioselective addition of alkylzinc reagents to aldehydes catalyzed by nickel complexes with α-amino amide ligands
Escorihuela, Jorge,Burguete, M. Isabel,Ujaque, Gregori,Lledós, Agustí,Luis, Santiago V.
supporting information, p. 11125 - 11136 (2016/12/07)
The enantioselective alkylation of aldehydes catalysed by nickel(ii)-complexes derived from α-amino amides was studied by means of density functional theory (DFT) and ONIOM (B3LYP:UFF) calculations. A mechanism was proposed in order to investigate the origin of enantioselectivity. The chirality-determining step for the alkylation was the formation of the intermediate complexes with the involvement of a 5/4/4-fused tricyclic transition state. The predominant products predicted theoretically were of (S)-configuration, in good agreement with experimental observations. The scope of the reaction was examined and high yields and enantioselectivities were observed for the enantioselective addition of Et2Zn and Me2Zn to aromatic and aliphatic aldehydes.
Synthetic tripeptides as alternate substrates of murein peptide ligase (Mpl)
Hervé, Mireille,Kova?, Andreja,Cardoso, Cécile,Patin, Delphine,Brus, Boris,Barreteau, Hélène,Mengin-Lecreulx, Dominique,Gobec, Stanislav,Blanot, Didier
, p. 1120 - 1126 (2013/07/05)
Murein peptide ligase (Mpl) is an enzyme found in Gram-negative bacteria. It catalyses the addition of tripeptide l-Ala-γ-d-Glu-meso-diaminopimelate to nucleotide precursor UDP-N-acetylmuramic acid during the recycling of peptidoglycan. Although not essential, this enzyme represents an interesting target for antibacterial compounds through the synthesis of alternate substrates whose incorporation into peptidoglycan might be deleterious for the bacterial cell. Therefore, we have synthesised 10 tripeptides l-Ala-γ-d-Glu-Xaa in which Xaa represents amino acids different from diaminopimelic acid. Tripeptide with Xaa = ε-d-Lys proved to be an excellent substrate of Escherichia coli Mpl in vitro. Tripeptides with Xaa = p-amino- or p-nitro-l-phenylalanine were poor substrates, while tripeptides with Xaa = d- or l-2-aminopimelate, dl-2-aminoheptanoic acid, l-Glu, l-norleucine, l-norvaline, l-2-aminobutyric acid or l-Ala were not substrates at all. Although a good Mpl substrate, the d-Lys-containing tripeptide was devoid of antibacterial activity against E. coli, presumably owing to poor uptake.
C2 symmetrical nickel complexes derived from α-amino amides as efficient catalysts for the enantioselective addition of dialkylzinc reagents to aldehydes
Escorihuela, Jorge,Altava, Belen,Burguete, M. Isabel,Luis, Santiago V.
, p. 551 - 558 (2013/07/27)
A series of C2 symmetrical 1:2 Ni:L complexes derived from α-amino amides were studied for the enantioselective addition of dialkylzinc reagents to aldehydes. Different structural elements on the ligands seem to play an important role in determining the observed enantioselectivity. Through optimization of structure and reaction conditions, the best ligand provided secondary alcohols in excellent yields (up to 98%) and enantioselectivity of up to 99% ee for (R)-enantiomer. A transition state model has been proposed to explain the observed enantioselectivities based on computational calculations at the DFT level. Very interestingly, calculations suggest a coordination model of the aldehyde to the metal complex through association of a lone pair of the carbonyl oxygen to the hydrogen atom of an amino group.
Efficient access to enantiopure γ4-amino acids with proteinogenic side-chains and structural investigation of γ4- asn and γ4-ser in hybrid peptide helices
Jadhav, Sandip V.,Misra, Rajkumar,Singh, Sumeet K.,Gopi, Hosahudya N.
supporting information, p. 16256 - 16262 (2013/12/04)
Hybrid peptides composed of α- and β-amino acids have recently emerged as new class of peptide foldamers. Comparatively, γ- and hybrid γ-peptides composed of γ4-amino acids are less studied than their β-counterparts. However, recent investigations reveal that γ4-amino acids have a higher propensity to fold into ordered helical structures. As amino acid side-chain functional groups play a crucial role in the biological context, the objective of this study was to investigate efficient synthesis of γ4-residues with functional proteinogenic side-chains and their structural analysis in hybrid-peptide sequences. Here, the efficient and enantiopure synthesis of various N- and C-terminal free-γ4-residues, starting from the benzyl esters (COOBzl) of N-Cbz-protected (E)-α,β-unsaturated γ-amino acids through multiple hydrogenolysis and double-bond reduction in a single-pot catalytic hydrogenation is reported. The crystal conformations of eight unprotected γ4-amino acids (γ4-Val, γ4-Leu, γ4-Ile, γ4-Thr(OtBu), γ4-Tyr, γ4-Asp(OtBu), γ4- Glu(OtBu), and γ-Aib) reveals that these amino acids adopted a helix favoring gauche conformations along the central Cγi￡ Cβ bond. To study the behavior of γ4- residues with functional side chains in peptide sequences, two short hybrid γ-peptides P1 (Ac-Aib-γ4-Asn-Aib-γ4-Leu- Aib-γ4-Leu-CONH2) and P2 (Ac-Aib- γ4-Ser-Aib-γ4-Val-Aib-γ4-Val- CONH2) were designed, synthesized on solid phase, and their 12-helical conformation in single crystals were studied. Remarkably, the γ4-Asn residue in P1 facilitates the tetrameric helical aggregations through interhelical H bonding between the side-chain amide groups. Furthermore, the hydroxyl side-chain of γ4-Ser in P2 is involved in the interhelical H bonding with the backbone amide group. In addition, the analysis of 87 γ4-residues in peptide single-crystals reveal that the γ4-residues in 12-helices are more ordered as compared with the 10/12- and 12/14-helices. Copyright
Enantioselective nickel-catalyzed conjugate addition of dialkylzinc to chalcones using chiral α-amino amides
Escorihuela, Jorge,Burguete, M. Isabel,Luis, Santiago V.
scheme or table, p. 6885 - 6888 (2009/04/07)
A series of α-amino amides derived from natural amino acids (alanine, valine, phenylalanine, isoleucine, and phenylglycine) have been synthesized and fully characterized. Their Ni(II) complexes prepared from Ni(acac)2 catalyze the enantioselective conjugate addition of diethylzinc to chalcones in high yields and in good enantioselectivities (up to 84%). The side chain of the amino acid and the substituents in the amide nitrogen govern the enantioselectivity of the catalytic process.
Synthesis of potent water-soluble tissue transglutaminase inhibitors
Griffin, Martin,Mongeot, Alexandre,Collighan, Russell,Saint, Robert E.,Jones, Richard A.,Coutts, Ian G.C.,Rathbone, Daniel L.
scheme or table, p. 5559 - 5562 (2009/05/30)
Dipeptide-based sulfonium peptidylmethylketones derived from 6-diazo-5-oxo-l-norleucine (DON) have been investigated as potential water-soluble inhibitors of extracellular transglutaminase. The lead compounds were prepared in four steps and exhibited pote
Coordination chemistry of phosphanyl amino acids: Solid state and solution structures of neutral and cationic rhodium complexes
Meyer, Christian,Scherer, Markus,Schoenberg, Hartmut,Rueegger, Heinz,Loss, Sandra,Gramlich, Volker,Gruetzmacher, Hansjoerg
, p. 137 - 148 (2007/10/03)
Copper phosphide or arsenide complexes, [Cu(EPh2)(neo)] (E = P, As, neo = 2,9-dimethyl-1,10-phenanthroline; trivial name: neocuprine) react selectively with the N-protected brominated serine derivatives, 2-(S)-(alkoxycarbonylamino)-3-bromomethy
A simple synthesis and determination of alkali metal binding selectivities of chiral macrocyclic tetraamides derived from L-alanine
Szczepanska,Tarnowski,Jurczak
, p. 1909 - 1917 (2007/10/03)
Chiral α,ω-diamines react under high-pressure conditions (10 kbar) with α,ω-dicarboxylates to give chiral cyclic tetraamides having C2-symmetry. The alkali metal (Li+, Na+, K+, Rb+, and Cs+
