A new cyclic nonapeptide, segetalin F, has been isolated from the seeds of Vaccaria segetalis and the structure including absolute stereochemistry was elucidated by using 2D NMR and chemical means. A series of segetalins showed a vasorelaxant activity against norepinephrine (NE)-induced contractions of rat aorta.
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http://dx.doi.org/10.1016/j.bmcl.2006.06.083 | DOI Listing |
Chembiochem
October 2024
Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstraße 34, 04103, Leipzig, Germany.
The chemokine-like receptor 1 (CMKLR1) is activated by the adipokine and chemoattractant protein chemerin. Cryo-EM structures of chemerin-9-CMKLR1-Gi have been published, where chemerin-9 is the nonapeptide of the C terminus of chemerinS157. Chemerin-9 is as active as the full-length protein in Ca-release but shows differences in equilibrium read-outs.
View Article and Find Full Text PDFRSC Med Chem
June 2024
Institute of Pathology, School of Medicine and Health, Technische Universität München Munich Germany.
In a recent paper in this journal (, 2023, , 2429), we described an unusually strong impact of regiospecific exchange of phenylalanines by tyrosines in 10 gallium-68-labeled trimers of certain cyclic RGD peptides, c[XRGDLAXp(Me)K] (X = F or Y), on non-specific organ uptakes. We found that there was, in part, no correlation of liver uptake with established polarity proxies, such as the octanol-water distribution coefficient (log ). Since this observation could not be explained straightforwardly, we suggested that the symmetry of the compounds had resulted in a synergistic interaction of certain components of the macromolecules.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
March 2024
College of Pharmacy, Hebei Medical University Shijiazhuang 050017, China.
Cyclopeptides isolated from a variety of plants are a class of cyclic nitrogen-containing compounds, and they are primarily formed by peptide bonds between amino acids, generally containing 2 to 37 L-configuration encoded or non-encoded amino acid residues. Cyclopeptides have significant values in scientific research as natural small-molecule metabolites produced by plants. The available studies have revealed that such natural products are ubiquitous in plants, which mainly include cyclic dipeptides, cyclic tetrapeptides, cyclic pentapeptides, cyclic hexapeptides, cyclic heptapeptides, cyclic octapeptides, cyclic nonapeptides, and cyclic decapeptides.
View Article and Find Full Text PDFBioorg Chem
April 2024
School of Medicine, Shanghai University, Shanghai 200444, China. Electronic address:
Antimicrobial photodynamic therapy (PDT) is a promising alternative to antibiotics for eradicating pathogenic bacterial infections. It holds advantage of not inducing antimicrobial resistance but is limited for the treatment of gram-negative bacterial infection due to the lack of photosensitizer (PS) capable of targeted permeating the outer membrane (OM) of gram-negative bacteria. To facilitate the targeted permeability of PS, cyclic polymyxin b nonapeptide that can specifically bind to the lipopolysaccharide on OM, is conjugated to an FDA approved PS chlorin e6 via variable linkers.
View Article and Find Full Text PDFInorg Chem
February 2024
Department of Chemistry, Trinity University, San Antonio, Texas 78212, United States.
The energetic and geometric features enabling redox chemistry across the copper cupredoxin fold contain key components of electron transfer chains (ETC), which have been extended here by templating the cross-β bilayer assembly of a synthetic nonapeptide, HHQALVFFA-NH (K16A), with copper ions. Similar to ETC cupredoxin plastocyanin, these assemblies contain copper sites with blue-shifted ( 573 nm) electronic transitions and strongly oxidizing reduction potentials. Electron spin echo envelope modulation and X-ray absorption spectroscopies define square planar Cu(II) sites containing a single His ligand.
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