Crystals of aza-beta3-peptides have been obtained. This gives the first opportunity for hydrazino peptides, in the sense of oligomers built exclusively with alpha-hydrazinoacetic units, to be observed in the solid state. The structures make it clear that the H-bond network developed by aza-beta3-peptides differs radically from those of the corresponding beta3-peptides but strongly resembles that of the alpha-aminoxy peptides. Our study contributes to the current interest in hydrazino peptides as an extension of the beta-peptide concept.
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http://dx.doi.org/10.1021/jo050938g | DOI Listing |
Beilstein J Org Chem
December 2024
UMR 8076, BioCIS, CNRS, Université Paris-Saclay, avenue des sciences, 91400 Orsay, France.
The synthesis of tripeptides incorporating new fluorinated heterocyclic hydrazino acids, based on the tetrahydropyridazine scaffold is described. Starting from simple fluorinated hydrazones, these non-proteinogenic cyclic β-amino acids were easily prepared by a zinc-catalyzed aza-Barbier reaction followed by an intramolecular Michael addition. Preliminary conformational studies on tripeptides including this scaffold in the central position show an extended conformation in solution (NMR) and in the solid state (X-ray).
View Article and Find Full Text PDFBioconjug Chem
December 2024
Department of Nuclear Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
Plectin, a scaffolding protein overexpressed in tumor cells, plays a significant role in hepatocellular carcinoma (HCC) proliferation, invasion, and migration. However, the use of L-type peptides for targeting plectin is hindered by their limited stability and retention. We designed a D-type plectin-targeting peptide (PTP) and developed a novel single-photon emission computed tomography (SPECT) probe for HCC imaging.
View Article and Find Full Text PDFMethods Enzymol
June 2024
University of Notre Dame, Notre Dame, IN, United States. Electronic address:
N-alkylated glycine residues are the main constituent of peptoids and peptoid-peptide hybrids that are employed across the biomedical and materials sciences. While the impact of backbone N-alkylation on peptide conformation has been extensively studied, less is known about the effect of N-amination on the secondary structure propensity of glycine. Here, we describe a convenient protocol for the incorporation of N-aminoglycine into host peptides on solid support.
View Article and Find Full Text PDFACS Omega
May 2024
Slovenian NMR Centre, National Institute of Chemistry, Ljubljana 1000, Slovenia.
In this work, we have applied the concept of α-hydrazino acid insertion in a peptide sequence as a means of structurally organizing a potential protein-protein interactions (PPI) inhibitor. Hydrazino peptides characterized by the incorporation of an α-hydrazino acid at specific positions introduce an additional nitrogen atom into their backbone. This modification leads to a change in the electrostatic properties of the peptide and induces the restructuring of its hydrogen bonding network, resulting in conformational changes toward more stable structural motifs.
View Article and Find Full Text PDFChem Sci
May 2024
Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla and Centro de Innovación en Química Avanzada (ORFEO-CINQA) C/ Prof. García González, 1 41012 Sevilla Spain
Catalysts generated by the combination of pyridine-hydrazone ,-ligands and Pd(TFA) have been applied to the addition of arylboronic acids to formylphosphonate-derived hydrazones, yielding α-aryl α-hydrazino phosphonates in excellent enantioselectivities (96 → 99% ee). Subsequent removal of the benzyloxycarbonyl (Cbz) -protecting group afforded key building blocks en route to appealing artificial peptides, herbicides and antitumoral derivatives. Experimental and computational data support a stereochemical model based on aryl-palladium intermediates in which the phosphono hydrazone coordinates in its -configuration, maximizing the interactions between the substrate and the pyridine-hydrazone ligand.
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