84890-98-2Relevant academic research and scientific papers
General, Mild, and Metal-Free Synthesis of Phenyl Selenoesters from Anhydrides and Their Use in Peptide Synthesis
Temperini, Andrea,Piazzolla, Francesca,Minuti, Lucio,Curini, Massimo,Siciliano, Carlo
, p. 4588 - 4603 (2017/05/12)
A mild, practical, and simple procedure for phenyl selenoesters synthesis from several anhydrides and diphenyl diselenide was developed. This transition-metal-free method provides a straightforward entry to storable Fmoc-amino acid selenoesters which are effective chemoselective acylating reagents. An application to oligopeptide synthesis was illustrated.
C9/12 Ribbon-Like Structures in Hybrid Peptides Alternating α- and Thiazole-Based γ-Amino Acids
Bonnel, Clément,Legrand, Baptiste,Simon, Matthieu,Martinez, Jean,Bantignies, Jean-Louis,Kang, Young Kee,Wenger, Emmanuel,Hoh, Francois,Masurier, Nicolas,Maillard, Ludovic T.
supporting information, p. 17584 - 17591 (2017/12/15)
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.
Synthesis of protected enantiopure (R) and (S)-α-trifluoromethylalanine containing dipeptide building blocks ready to use for solid phase peptide synthesis
Devillers, Emmanuelle,Pytkowicz, Julien,Chelain, Evelyne,Brigaud, Thierry
, p. 1457 - 1468 (2016/06/13)
Considering the increasing importance of fluorinated peptides, the development of efficient and reliable synthetic methods for the incorporation of unnatural fluorinated amino acids into peptides is a current matter of interest. In this study, we report t
Identification of Pyridine Synthase Recognition Sequences Allows a Modular Solid-Phase Route to Thiopeptide Variants
Wever, Walter J.,Bogart, Jonathan W.,Bowers, Albert A.
supporting information, p. 13461 - 13464 (2016/10/31)
Thiopeptides are structurally complex, bioactive natural products derived from ribosomally synthesized and post-translationally modified peptides. A remarkable set of enzymes were recently revealed to catalyze the formation of the core trithiazolylpyridine of thiopeptides via a formal [4 + 2] cycloaddition. These pyridine synthases typically act late in thiopeptide biosynthesis to affect macrocyclization and cleavage of the N-terminal leader peptide, making them potentially useful biocatalysts for preparation of new thiopeptide variants. Herein we investigate the leader peptide requirements for TclM from thiocillin biosynthesis in Bacillus cereus ATCC 14579. Through a series of truncations, we define a minimum recognition sequence (RS) that is necessary and sufficient for TclM activity. This RS can be readily synthesized and ligated to linear thiopeptide cores prepared via solid-phase peptide synthesis (SPPS), giving an efficient and modular route to thiopeptide variants. We exploit this strategy to define C-terminal core peptide requirements and explore the differences in promiscuity of two pyridine synthases, TclM and TbtD, ultimately examining their ability to access new structural variants.
Synthesis of novel cinchona-amino acid hybrid organocatalysts for asymmetric catalysis
Barrulas, Pedro,Benaglia, Maurizio,Burke, Anthony J.
, p. 923 - 935 (2014/07/22)
Three novel subclasses of cinchonidine derivatives coupled to diverse amino acids were prepared in very good overall yield and tested in a benchmark organocatalytic aldol reaction, between acetone and aromatic aldehydes. These subclasses are a family of a
α-N-Protected dipeptide acids: A simple and efficient synthesis via the easily accessible mixed anhydride method using free amino acids in DMSO and tetrabutylammonium hydroxide
Verardo,Gorassini
, p. 315 - 324 (2013/06/05)
The importance of dipeptides both in medicinal and pharmacological fields is well documented and many efforts have been made to find simple and efficient methods for their synthesis. For this reason, we have investigated the synthesis of α-N-protected dipeptide acids by reacting the easily accessible mixed anhydride of α-N-protected amino acids with free amino acids under different reaction conditions. The combination of TBA-OH and DMSO has been found to be the best to overcome the low solubility of amino acids in organic solvents. Under these experimental conditions, the homogeneous phase condensation reaction occurs rapidly and without detectable epimerization. The present method is also applicable to side-chain unprotected Tyr, Trp, Glu, and Asp but not Lys. This latter residue is able to engage two molecules of mixed anhydride giving the corresponding isotripeptide. Moreover, the applicability of this protocol for the synthesis of tri- and tetrapeptides has been tested. This approach reduces the need for protecting groups, is cost effective, scalable, and yields dipeptide acids that can be used as building blocks in the synthesis of larger peptides.
Sodium borohydride reduction of carbamoyl azide function: A synthesis of N-protected N'-formyl-gem-diaminoalkyl derivatives
Verardo, Giancarlo,Gorassini, Andrea
, p. 5387 - 5397 (2013/09/02)
A simple, efficient two-step synthesis of N-protected N′-formyl-gem- diaminoalkyl derivatives is reported. The procedure involves the unprecedented reduction of the carbamoyl azide of α-N-Boc/Fmoc/Z-protected amino acids and dipeptides (Boc = tert-butoxycarbonyl, Fmoc = 9-fluorenylmethoxycarbonyl, Z = benzyloxycarbonyl) by treatment with NaBH4 at room temperature. The reaction proceeds rapidly (45 min) without detectable epimerization (by HPLC-ESI-MS analysis) and is not influenced by the nature of the starting carbamoyl azide. The 1H and 13C NMR analyses of the synthesized N-protected N′-formamides were carried out in [D 6]DMSO. The spectra exhibited the presence of two rotameric forms in solution as a result of the restricted rotation around the N-CO formyl bond. The integration of the N-CH-N protons of the two isomers showed that the cis isomer (rotamer B) was the more abundant conformer by 60 to 78 %. The reported synthesis represents the potential value of carbamoyl azides as versatile chiral starting materials for many synthetic purposes. A simple two-step synthesis of N-protected N′-formyl-gem-diaminoalkyl derivatives is reported that employs the reduction of the carbamoyl azide of N-protected amino acids and N-protected dipeptide acids with NaBH4. This racemization-free protocol is compatible with the most commonly used N-protecting groups. Copyright
Characterization of Nα-Fmoc-protected ureidopeptides by electrospray ionization tandem mass spectrometry (ESI-MS/MS): Differentiation of positional isomers
Ramesh,Raju,Srinivas,Sureshbabu,Narendra,Vasantha
experimental part, p. 1461 - 1472 (2011/09/15)
Four pairs of positional isomers of ureidopeptides, FmocNH-CH(R 1)-φ(NH-CO-NH)-CH(R2)-OY and FmocNH-CH(R 2)-φ(NH-CO-NH)-CH(R1)-OY (Fmoc = [(9-fluorenyl methyl)oxy]carbonyl; R1 = H, alkyl; R2/sub
Small molecule microarray-facilitated screening of affinity-based probes (AfBPs) for γ-secretase
Shi, Haibin,Liu, Kai,Xu, Ashley,Yao, Shao Q.
supporting information; experimental part, p. 5030 - 5032 (2010/01/06)
A small molecule microarray (SMM) platform is developed herein, which enables high-throughput discovery of affinity-based probes (AfBPs) against γ-secretase.
Synthesis of ureidopeptides using pentafluorophenyl carbamates from N a-Fmoc-peptide acids
Sureshbabu, Vommina V.,Venkataramanarao, Rao
, p. 910 - 919 (2008/12/23)
Highly active and shelf stable pentafluoro phenol derived Fmoc-peptidyl carbamates have been synthesized from corresponding Fmoc-peptidyl isocyanates. The utility of pentafluorophenyl carbamate intermediates has been demonstrated by the synthesis of tri, penta and hexapeptidyl ureas which are obtained in good yields. All the synthesised compounds have been characterized by 1H NMR, 13C NMR and mass spectroscopy. The coupling reaction using pentafluorophenyl carbamates to insert urea bond between α amino acids is fast, clean and high yielding.
