Unique β‐Turn Peptoid Structures and Their Application as Asymmetric Catalysts

Abstract

Peptoids, N‐substituted glycine oligomers, represent an important class of peptidomimetics that can fold into three‐dimensional structures in solution. Most of the folded peptoid structures, however, resemble helices, and this can limit their applications, specifically in asymmetric catalysis. In this work, for the first time, unique examples of pyrrolidine‐based β‐turn‐like peptoids are described and characterized, both in the solid state, by single‐crystal X‐ray analysis, and in solution, by circular dichroism spectroscopy. Furthermore, their highly efficient and enantioselective catalytic activity for the production of γ‐nitro aldehydes by asymmetric Michael reaction in water was demonstrated. The structural properties and DFT‐D3 calculations of the new β‐turn‐like peptoids, as well as catalytic and spectroscopic studies on designed pyrrolidine‐based helical peptoids, suggest that the β‐turn structure plays a key role in the stereoselectivity of the catalytic reaction.

Elaborate Supramolecular Architectures Formed by Co-Assembly of Metal Species and Peptoid Macrocycles

“…However, the strategic incorporation of particular side chain types, the ingenious formation of long-range interactions between functional groups, and macrocyclization allow researchers to obtain stable structural motifs. Peptoid secondary structures now include polyproline type-I and type-II helices, − a “threaded-loop” conformation, peptoid ribbons, , a square-shaped η-helix, ω-strands, Σ-strands, and turn or loop structures. − …”

Effect of ultrasonic treatment on the activity of sugar metabolism relative enzymes and quality of coconut water

“…And β-turn typically consists of a positive peak at 207.5 or 209 nm and a negative peak near 227 nm. Meanwhile, random coils are characterized by a single peak below 200 nm [41] , [42] . CD spectra of US-treated AI at different time and power are shown in Fig.…”

A Water‐Soluble Peptoid that Can Extract Cu2+ from Metallothionein via Selective Recognition

“…As the combination between terpy and HQ within a non‐helical peptoid did not produce a selective chelator for Cu 2+ , [4] and because terpy has higher affinity for Zn 2+ than to Cu 2+ in water, [15] we decided to synthesize a peptoid trimer that incorporates HQ and 2‐picolyl amine ( N pam) as co‐ligands, and Nspe at the C‐terminus, for enabling the pre‐organization of the metal‐binding ligands ( PCA‐HQ , Figure 1). [13a–d] Along with PCA‐HQ , which includes the N, O donor ligand HQ, we designed a similar peptoid that incorporates a N,N donor‐based co‐ligand and chose 2,2’‐bipyridine (bipy) owing to its known affinity for Cu 2+ ( PCA‐Nspe , Figure 1). [11a, 12a, 13c] The peptoids were synthesized on Rink amide resin using a previously reported modified protocol, [11f,j] cleaved from the solid support and purified by HPLC (>99 % purity).…”