We have designed and evaluated 45 linear analogues of the natural constrained cyclopeptide TMC-95A. These synthetically less demanding molecules are based on the tripeptide sequence Y-N-W of TMC-95A. Structural variations in the amino acid side chains and termini greatly influenced both the efficiency and selectivity of action on a given type of active site. Inhibition constants were submicromolar (K-i approximate to 300 nM) despite the absence of the entropically favorable constrained conformation that is characteristic of TMC-95A and its cyclic analogues. These linear compounds were readily prepared and reasonably stable in culture medium and could be optimized to inhibit one, two, or all three proteasome catalytic sites. Cytotoxicity assays performed on a series of human tumor cell lines identified the most potent inhibitors in cells.
Synthesis of Silacyclic Dipeptides: Peptide Elongation at Both N- and C-Termini of Dipeptide
作者:Tomohiro Hattori、Hisashi Yamamoto
DOI:10.1021/jacs.1c11260
日期:2022.2.2
A new type of peptide bond formation utilizing silacyclic aminoacids or peptides is described. This work has the following advantages: (1) imidazolylsilane is a highly fascinating coupling reagent for dipeptide synthesis from N-,C-terminal unprotected aminoacids with aminoacid tert-butyl esters; (2) deprotection of the tert-butyl ester at the C-terminus and cyclization sequentially proceed depending
Total Synthesis of Cyclotheonamide C by Use of an α-Keto Cyanophosphorane Methodology for Peptide Assembly
作者:Stéphane P. Roche、Sophie Faure、Lahssen El Blidi、David J. Aitken
DOI:10.1002/ejoc.200800591
日期:2008.10
The totalsynthesis of cyclotheonamideC (3), a macrocyclic pentapeptide incorporating an alpha-keto homoarginine (k-Arg) and a vinylogous dehydrotyrosine (V-deltaTyr) unit, has been achieved. For comparison of macrocyclisation feasibility, two linear pentapeptides bearing free ketone functions at the k-Arg units were prepared, by use of tandem oxidation/coupling reactions on alpha-keto cyanophosphorane
Cyclotheonamide C (3) 的全合成已经实现,这是一种大环五肽,结合了 α-酮基高精氨酸 (k-Arg) 和乙烯基脱氢酪氨酸 (V-deltaTyr) 单元。为了比较大环化的可行性,通过使用α-酮基氰基正膦前体的串联氧化/偶联反应作为制备五肽的关键过程,制备了两种在 k-Arg 单元上带有游离酮功能的线性五肽。五肽 V-deltaTyr C 末端的成功激活和偶联导致目标分子核心,从而提供了目标化合物的短全合成