A series of 9-(acylamino)doxycycline derivatives has been prepared. These analogs exhibit good activity against both tetracycline sensitive and tetracycline resistant Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria that are encoded with the efflux and ribosomal resistance gene factors. N,N-Dialkylglycylamido derivatives possessed the highest activity. Replacement of glycine moiety with other amino acids did not further enhance the activity.
Total Synthesis of the Antifungal Depsipeptide Petriellin A
作者:Marianne M. Sleebs、Denis Scanlon、John Karas、Rani Maharani、Andrew B. Hughes
DOI:10.1021/jo201017w
日期:2011.8.19
We report the solid-phase totalsynthesis of the antifungal highly modified cyclic depsipeptide petriellin A. The synthesis confirms earlier reports on the absolute configuration of the natural product. The solid-phase approach resulted in a protected linear precursor, which was cleaved from the solid support prior to cyclization and final deprotection. Use of advanced coupling agents for several hindered
new family of uronium salts (HTMU, HMMU, and HDmPyMU) based on isonitroso Meldrum's acid (HONM) are reported as stand-alone couplingreagents. Amide bond formation with the use of these reagents occurred more quickly than that with other uronium salts as a result of the presence of a neighboring group effect with a cyclic structure. Thus, these novel onium salts were often moreeffective in the acylation
Application of 2,2′‐dipyridyl disulfide‐mediated thiazolidine ring‐opening reaction to glycoprotein synthesis: Total chemical synthesis of evasin‐3
作者:Hidekazu Katayama、Koji Nagata
DOI:10.1002/psc.3290
日期:2021.2
Thiazolidine ring‐openingreaction is one of the key steps in protein chemical synthesis via sequential native chemical ligation strategy. We recently developed a novel thiazolidine ring‐openingreaction with 2,2′‐dipyridyl disulfide (DPDS). In order to investigate the applicability of this reaction to glycoprotein synthesis, we synthesized evasin‐3, a cysteine‐rich glycoprotein with chemokine‐binding
噻唑烷开环反应是通过顺序天然化学连接策略进行蛋白质化学合成的关键步骤之一。我们最近开发了一种新的噻唑烷与 2,2'-二吡啶基二硫化物 (DPDS) 的开环反应。为了研究该反应对糖蛋白合成的适用性,我们合成了 evasin-3,这是一种富含半胱氨酸的糖蛋白,具有最初在蜱唾液中发现的趋化因子结合能力。evasin-3的序列分为三个片段,这些片段分别用普通固相肽合成方法合成。在第一次连接中间和 C 端片段后,用作中间片段 N 端 Cys 残基保护基的噻唑烷用 DPDS 转化为 Cys。在这个噻唑烷开环反应中,N-连接的聚糖部分。在与 N 端片段的第二次连接和重折叠反应后,可以以良好的收率获得 evasin-3。合成的 evasin-3 显示出对 CXCL 趋化因子的特异性结合能力。这些结果清楚地表明这种 DPDS 方法可用于糖蛋白合成。
Functionalized polystyrene supports for solid-phase synthesis of glycyl-, alanyl-, and isoleucyl-RNA conjugates as hydrolysis-resistant mimics of peptidyl-tRNAs
作者:Jessica Steger、Ronald Micura
DOI:10.1016/j.bmc.2011.07.018
日期:2011.9
RNA-peptide conjugates that mimic amino acid-charged tRNAs and peptidyl-tRNAs are of high importance for structural and functional investigations of ribosomal complexes. Here, we present the synthesis of glycyl-, alanyl-, and isoleucyladenosine modified solid supports that are eligible for the synthesis of stable 3'-aminoacyl- and 3'-peptidyl-tRNA termini with an amide instead of the natural ester linkage. The present work significantly expands the range of accessible peptidyl-tRNA mimics for ribosomal studies. (C) 2011 Elsevier Ltd. All rights reserved.