The Glaser-Eglinton reaction between either two C or N propargylglycine (Pra or NPra) amino acids, in the presence of copper(II), led to cyclic hexa- and octapeptides constrained by a butadiyne bridge. The on-resin cyclization conditions were analyzed and optimized. The consequences of this type of constraint on the three dimensional structure of these hexapeptides and octapeptides were analyzed in details by NMR and molecular dynamics. We show that stabilized short cyclic peptides could be readily prepared via the Glaser oxidative coupling either with a chiral (Pra), or achiral (NPra) residue. The 1,3-butadiyne cyclization, along with disulfide bridged and lactam cyclized hexapeptides expands the range of constrained peptides that will allow exploring the breathing of amino acids around a β-turn structure.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.bmc.2014.10.026 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A Multistep Oxidative Cascade Reaction from a Naphthalenediol-Based Pre-Ligand to a Tetranuclear Perylenequinone-Based Fe Complex.
Chemistry
November 2024
Department of Chemistry, Bielefeld Universtity, Universitätsstr. 25, D-33615, Bielefeld, Germany.
We have developed a family of dinuclear complexes using 2,7-disubstituted 1,8-naphthalenediol ligands that bind by molecular recognition to two neighboring phosphate diesters of the DNA backbone with the dinuclear Cu and Ni complexes exhibiting a severe cytotoxicity for human cancer cells. To increase the binding affinity, we intended to synthesize the corresponding dinuclear Fe complex. Surprisingly, we obtained a tetranuclear Fe perylene-based complex instead of the expected dinuclear Fe naphthalene-based complex.
View Article and Find Full Text PDFAssessing antioxidant responses in C6 and U-87 MG cell lines exposed to high copper levels.
Comp Biochem Physiol C Toxicol Pharmacol
January 2025
Laboratório de Biologia Celular, Centro de Ciências Rurais, Coordenadoria Especial de Ciências Biológicas e Agronômicas, Universidade Federal de Santa Catarina (UFSC), Campus de Curitibanos, SC, Curitibanos, Brazil. Electronic address:
Copper excess has been tested as an anticancer therapy, due to its properties to generate oxidative stress resulting in tumoral cell death. Thus, this study aimed to evaluate the impact of copper excess on oxidative stress and antioxidant responses in glioma cells, establishing the antioxidant system as a target of copper toxicity in tumoral cells. C6 and U-87 MG cells were exposed to CuSO (0-600 μM) for 24-48 h.
View Article and Find Full Text PDFP2X7 receptor in macrophage polarization and its implications in neuroblastoma tumor behavior.
Purinergic Signal
October 2024
Metastasis Molecular Mechanisms Laboratory and Neurosciences Laboratory, Institute of Chemistry, Biochemistry Department, University of Sao Paulo, Sao Paulo, Brazil.
Tumor-associated macrophages (TAMs) exhibit antitumor or protumor responses related to inflammatory (or M1) and alternative (or M2) phenotypes, respectively. The P2X7 receptor plays a key role in macrophage polarization, influencing inflammation and immunosuppression. In this study, we investigated the role of the P2X7 receptor in TAMs.
View Article and Find Full Text PDFUnraveling the NH-SCR-DeNO Mechanism of Cu-SSZ-13 Variants by Spectroscopic and Transient Techniques.
ChemSusChem
November 2024
Institute of Chemical Technology, Universität Leipzig, Linnéstr. 3, 04103, Leipzig, Germany.
Commercial SSZ-13 zeolite with different n(Si)/n(Al) ratios and from different suppliers were subjected to a post-synthetic treatment in order to create mesopores of up to 15 nm. Furthermore, the materials were modified with copper ions and thoroughly physico-chemically characterized. The modified textural properties varied the nature of copper species, and thus, activity in the selective catalytic reduction of NO with ammonia (NH-SCR-DeNO).
View Article and Find Full Text PDFCorrection: 3D-printed wound dressing platform for protein administration based on alginate and zinc oxide tetrapods.
Nano Converg
July 2024
Department for Material Science, Functional Nanomaterials, Kiel University, Kiel, Germany.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!