A new strategy for the synthesis of polyamides from polyesters of hydroxyl-containing amino acids using a multi O-N acyl transfer reaction was developed. This original approach allowed the synthesis of three generations of polymers from the same starting monomer. The polymerization of N-benzyloxycarbonyl-serine and its γ-homologated derivative provided the Z-protected polyesters; then the water-soluble polycationic polyesters were obtained by removal of the Z-protecting group; and finally the polyamides were obtained by a base-induced multi O-N acyl transfer, both in aqueous or organic medium. The key step transfer reaction was monitored by the disappearance and appearance of characteristic NMR proton signals and IR bands of polyesters and polyamides.
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http://dx.doi.org/10.1002/marc.201100235 | DOI Listing |
Org Biomol Chem
January 2025
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 3010, Victoria, Australia.
Despite advances in solid phase peptide synthesis and peptide ligation, challenges remain in the assembly of polypeptides through coupling of peptide fragments. Herein we describe a new method for peptide fragment coupling employing the Ag(I)-promoted transformation of peptide thioamides. This process proceeds an isoimide-tethered intermediate, which undergoes an O-N acyl transfer to generate the polypeptide.
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June 2024
Chemistry Department, Faculty of Science, Al-Azhar University (Girls), Cairo, Egypt.
Sugar esters display surface-active properties, wetting, emulsifying, and other physicochemical phenomena following their amphipathic nature and recognize distinct biological activity. The development of nutritional pharmaceuticals and other applications remains of great interest. Herein, three novel homologous series of several N-mono-fatty acyl amino acid glucosyl esters were synthesized, and their physicochemical properties and biological activities were evaluated.
View Article and Find Full Text PDFNat Commun
February 2024
Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan.
GPR34 is a recently identified G-protein coupled receptor, which has an immunomodulatory role and recognizes lysophosphatidylserine (LysoPS) as a putative ligand. Here, we report cryo-electron microscopy structures of human GPR34-G complex bound with one of two ligands bound: either the LysoPS analogue S3E-LysoPS, or M1, a derivative of S3E-LysoPS in which oleic acid is substituted with a metabolically stable aromatic fatty acid surrogate. The ligand-binding pocket is laterally open toward the membrane, allowing lateral entry of lipidic agonists into the cavity.
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January 2024
Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, School of Pharmacy, Yantai University, Shandong, Yantai, 264005, P. R. China.
A palladium/norbornene catalyzed two-component coupling process involving acylation/cyanation of aryl iodides is reported. In this work, aryl acyl nitrile compounds are cleverly selected to provide both nitrile and acyl sources by palladium-catalyzed cleavage of the C-CN bond as both an electrophilic reagent and a termination reagent. This is the first example of C-CN bond cleavage bifunctionalization of aryl iodides.
View Article and Find Full Text PDFCarbohydr Res
February 2024
Department of Chemistry, University of Alberta, Edmonton Alberta, T6G 2G2, Canada. Electronic address:
Neuraminic acid (Neu5Ac, also known as sialic acid) is an important monosaccharide found in glycoproteins and glycolipids which plays a vital role in regulation of physiological functions and pathological conditions. The study of sialoglycans has benefitted from the development of glycomimetic probes and inhibitors for proteins and enzymes that interact with and modify neuraminic acid in glycan chains. Methods to access sialoside intermediates with high yield are needed to facilitate the design of new targets.
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