Investigation of the network of preferred interactions in an artificial coiled-coil association using the peptide array technique

• Raheleh Rezaei Araghi,
• Carsten C. Mahrenholz,
• Rudolf Volkmer and
• Beate Koksch

Beilstein J. Org. Chem. 2012, 8, 640–649, doi:10.3762/bjoc.8.71

• the concept of rational drug design based on coiled-coil proteins [6]. In this context, the use of unnatural amino acids in peptidomimetics is advisable, to enhance enzymatic stability, limit conformational flexibility, and improve pharmacodynamics and bioavailability [7]. In order to manipulate helix

Asymmetric synthesis of quaternary aryl amino acid derivatives via a three-component aryne coupling reaction

• Elizabeth P. Jones,
• Peter Jones,
• Andrew J. P. White and
• Anthony G. M. Barrett

Beilstein J. Org. Chem. 2011, 7, 1570–1576, doi:10.3762/bjoc.7.185

• . Incorporation of such units into peptidomimetics, not only affects lipophilicity, but also the secondary structure and hence the conformational rigidity, which can increase the resistance to enzymatic degradation [15][16][17][18][19]. Such units are also found in biologically interesting natural products, such

Multicomponent synthesis of artificial nucleases and their RNase and DNase activity

• Anton V. Gulevich,
• Lyudmila S. Koroleva,
• Olga V. Morozova,
• Valentina N. Bakhvalova,
• Vladimir N. Silnikov and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2011, 7, 1135–1140, doi:10.3762/bjoc.7.131

• anticancer drugs [2][3] and new therapeutics against RNA-containing viruses. Recently, a number of synthetic RNA-cleaving molecules (artificial ribonucleases) had been developed and tested in vitro [4][5][6][7][8][9][10][11]. Among numerous artificial ribonucleases, peptidomimetics showed evident advantages

• due to their lower cytotoxicity and elevated potential penetration into living eukaryotic cells. Moreover, a few dipeptides [12] were shown to induce interferon production, thus providing antivirus defence. Therefore, the development of new peptidomimetics with ribonuclease activity is an important

• diamides. The benzyl groups can be easily removed from compounds 4 by the standard hydrogenolysis procedure. For example, using Pd/C as catalyst we obtained the target peptidomimetics 5 in up to 90% yield. Thus, we synthesized a number of racemic peptidomimetics 4 and 5, containing aliphatic or aromatic

Novel synthesis of pseudopeptides bearing a difluoromethyl group by Ugi reaction and desulfanylation

• Jingjing Wu,
• Hui Li and
• Song Cao

Beilstein J. Org. Chem. 2011, 7, 1070–1074, doi:10.3762/bjoc.7.123

• cleavage; Ugi reaction; Introduction Fluorinated amino acids and pseudopeptides have increasingly attracted attention in recent years [1][2][3][4][5]. The selective incorporation of fluorine-containing groups, such as trifluoromethyl, difluoromethyl and difluoromethylene, into peptides or peptidomimetics

• reported of the preparation and bioassay of pseudopeptides and peptidomimetics bearing difluoromethyl groups. For example, compound I can act as bradykinin B1 antagonist or inverse agonist and can be used in the prevention of inflammation and pain [19]. Compound II is an inhibitor of microsomal

Long-range diastereoselectivity in Ugi reactions of 2-substituted dihydrobenzoxazepines

• Luca Banfi,
• Andrea Basso,
• Valentina Cerulli,
• Valeria Rocca and
• Renata Riva

Beilstein J. Org. Chem. 2011, 7, 976–979, doi:10.3762/bjoc.7.109

• stereoselectivity. In conclusion, the methodology presented herein appears particularly well suited for the stereoselective preparation of libraries of peptidomimetics based on the tetrahydrobenzoxazepine ring. Although structures of general formula 6 are unprecedented, other tetrahydrobenzoxazepines have shown

Oxalyl retro-peptide gelators. Synthesis, gelation properties and stereochemical effects

• Janja Makarević,
• Milan Jokić,
• Leo Frkanec,
• Vesna Čaplar,
• Nataša Šijaković Vujičić and
• Mladen Žinić

Beilstein J. Org. Chem. 2010, 6, 945–959, doi:10.3762/bjoc.6.106

• characteristics of gels formed by chiral bis(dipeptide)oxalamides. Structurally, such gelators belong to the group of retro-peptides, which have been intensively studied as peptidomimetics due to their higher proteolytic stability and bioavailability compared to natural counterparts [44][45][46][47]. Despite very

Synthesis of glycosylated β³-homo-threonine conjugates for mucin-like glycopeptide antigen analogues

• Florian Karch and
• Anja Hoffmann-Röder

Beilstein J. Org. Chem. 2010, 6, No. 47, doi:10.3762/bjoc.6.47

• development of diverse peptidomimetics for an increasing number of applications [22][23][24][25]. Therefore we contemplated the use of mucin-derived α/β-hybrid glycopeptides as stable mimetics of naturally occurring glycocopeptide antigens for cancer vaccines. We were surprised to see how little precedence

Enantioselective synthesis of tricyclic amino acid derivatives based on a rigid 4-azatricyclo[5.2.1.0^2,6]decane skeleton

• Matthias Breuning,
• Tobias Häuser,
• Christian Mehler,
• Christian Däschlein,
• Carsten Strohmann,
• Andreas Oechsner and
• Holger Braunschweig

Beilstein J. Org. Chem. 2009, 5, No. 81, doi:10.3762/bjoc.5.81

• β-turn-inducing building blocks in peptidomimetics and for chiral auxiliaries in asymmetric organocatalysis. Keywords: amino acid; enantioselective synthesis; norbornane; polycyclic compounds; pyrrolidine; Introduction Unnatural amino acids with a rigid bowl-shaped backbone have received

• ][8] are embedded in peptidomimetics (Figure 1). Enantioselective organocatalysis [9][10][11][12][13][14][15][16][17] is another field of application for conformationally rigid amino acid derivatives. In this context, focus was also put on derivatives in which the activating acidic group is anchored

• are promising candidates as ß-turn-inducing building blocks in peptidomimetics and as chiral auxiliaries in organocatalysis. The conformationally rigid amino acid derivatives 1–3 (β-turn-inducing building blocks) and 4–6 (successful organocatalysts). The targeted tricyclic amino acid derivatives 7 and

2-Phenyl- tetrahydropyrimidine- 4(1H)-ones – cyclic benzaldehyde aminals as precursors for functionalised β²-amino acids

• Markus Nahrwold,
• Arvydas Stončius,
• Anna Penner,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2009, 5, No. 43, doi:10.3762/bjoc.5.43

• . In the course of this study, an L-asparagine derivative was condensed with benzaldehyde and subsequently converted to orthogonally protected (R)-β2-homoaspartate. Keywords: β2-amino acids; cyclocondensation; diastereoselective alkylation; N,N-acetals; peptidomimetics; ring opening; self-regeneration

• stable secondary structures even at a very short chain lengths [2][3]. β-Peptides are metabolically stable peptidomimetics that have proved to be inert to enzymatic proteolysis both in vitro [4][5] and in vivo [6]. As a first biologically active example, the β-tetrapeptide Ac-β3hThr-β2hLys-β3hTrp-β3hPhe

Synthesis of new C^α-tetrasubstituted α-amino acids

• Andreas A. Grauer and
• Burkhard König

Beilstein J. Org. Chem. 2009, 5, No. 5, doi:10.3762/bjoc.5.5

• -turns [6], or 310- or α-helices [7][8][9][10][11]. Cα-Tetrasubstituted α-amino acids are therefore of importance for the synthesis of peptides or peptidomimetics with properties such as increased chemical and metabolic stability, increased hydrophobicity, or increased conformational constraints [12][13

Synthesis of new triazole- based trifluoromethyl scaffolds

• Michela Martinelli,
• Thierry Milcent,
• Sandrine Ongeri and
• Benoit Crousse

Beilstein J. Org. Chem. 2008, 4, No. 19, doi:10.3762/bjoc.4.19

• derivatives to afford 1,4-disubstituted 1,2,3-triazoles through a Huisgen 1,3-dipolar cycloaddition. The reaction is catalyzed by a Cu(I) species in acetonitrile, and the corresponding products are obtained in good yields. This process thus offers an entry to new trifluoromethyl peptidomimetics as interesting

• scaffolds. Keywords: copper; catalysis; fluorine; heterocycle; click chemistry; peptidomimetics; Background The 1,2,3-triazole system has widespread uses, and it has been considered as an interesting component in terms of biological activity [1][2][3][4][5]. Although the use of heterocyclic moieties in

• peptidomimetics has been widely reported [6], the application of 1,2,3-triazoles in the field of conformational studies has occurred only recently [7][8][9][10][11][12][13]. In particular, Angelo and co-workers [8][12] reported the synthesis of triazole foldamers able to adopt specific protein-like conformations

Indolizidines and quinolizidines: natural products and beyond

• Joseph P. Michael

Beilstein J. Org. Chem. 2007, 3, No. 27, doi:10.1186/1860-5397-3-27

• being invested in the development of innovative methods for preparing the parent bicyclic systems and, more especially, for the stereocontrolled attachment of substituents. Studies on the biological activity of compounds containing azabicyclic building blocks (for example, rigid bicyclic peptidomimetics