Post-Polymerization Modification of Poly(L-glutamic acid) with D-(+)-Glucosamine

Abstract

Carboxyl functional groups of poly(L-glutamic acid) (PGlu) were modified with a D-(+)-glucosamine (GlcN) by amidation using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling reagent. The coupling reaction was performed in aqueous medium without protection of hydroxyl functional groups of D-(+)-glucosamine. Poly(L-glutamic acid) and GlcN functionalized polyglutamates (P(Glu-GlcN)) were thoroughly characterized by 1D and 2D NMR spectroscopy and SEC-MALS to gain detailed information on their structure, composition and molar mass characteristics. The results reveal successful functionalization with GlcN through the amide bond and also to a minor extent through ester bond formation in position 1 of GlcN. In addition, a ratio between the α-and β-form of glucosamine substituent coupled to polyglutamate repeating units as well as the content of residual dimethoxy triazinyl active ester moiety in the samples were evaluated.

Turning Peptide Sequences into Ribbon Foldamers by a Straightforward Multicyclization Reaction

“…[6] Herein, we propose as trategy to generate novel folded architectures based on a-amino-g-lactam derivatives (Agl-AA x with AA x = amino acid), so-called Freidingers lactams, [9,10] widely used as type II b-turn inducers in relevant bioactive peptides. [11] This strategy has several advantages. First, only a-amino acids are used as starting material, enabling easy access to these new foldamers and the possibility of using conventional solid-phase peptide synthesis (SPPS) methods.S econd, the structurally constrained blocks are generated in the course of the SPPS,a voiding the preparation of each dipeptide lactam unit prior to the construction of the oligomers.S olid-phase methods for the on-line synthesis of peptides containing as ingle a-amino-glactam unit have been reported.…”

Synthesis and Self‐assembly of a Helical Polymer Grafted from a Foldable Polyurethane Scaffold

“…4.2 Synthesis of γ‐benzyl‐ l ‐glutamate NCA : NCA of γ ‐ benzyl‐ l ‐glutamate was synthesized following the reported procedure . 2.0 g (0.0084 moles) of l ‐glutamic acid γ‐benzyl ester was taken in a round bottom flask.…”

“…4.2 Synthesis of g-benzyl-l-glutamate NCA: NCA of g-benzyl-lglutamate was synthesized following the reported procedure. [12] 2.0 g( 0.0084 moles) of l-glutamic acid g-benzyl ester was taken in ar ound bottom flask. Then 40 mL dry tetrahydrofuran (THF) was added under nitrogen gas and mixture was cooled in an ice bath and to this solution, triphosgene (1 g, 0.0033 moles) was added slowly with constant stirring.…”

Designing polymers with sugar-based advantages for bioactive delivery applications

“…The latter approach ensures the presence of sugar moieties on the formulation (e.g., nanoparticles) surface to enable cellular interaction, making it especially suitable for targeted delivery. Glycosylation can be chemically achieved through reductive amination [12], click chemistry for alkyne bearing polymers [28, 29], coupling reactions for conjugation via ester or amide [26, 30], and enzymatic transglycosylation [12]. Click chemistry is beneficial for quantitative carrier glycosylation [29], as it allows for precise control over the degree of glycosylation.…”