straightforward synthesis of acylating reagents such as Weinreb and MAP amides fromaromatic, aliphatic carboxylic acids, and amino acids using PPh3/NBS combination is described. A chemo-selective modification of the carboxylic acid group into Weinreb amide in the presence of more reactive aldehydes and ketones is presented. All reactions were performed at ambient temperature under air using undried commercial
Discovery of a Novel Class of Potent HCV NS4B Inhibitors: SAR Studies on Piperazinone Derivatives
作者:Ramesh Kakarla、Jian Liu、Devan Naduthambi、Wonsuk Chang、Ralph T. Mosley、Donghui Bao、Holly M. Micolochick Steuer、Meg Keilman、Shalini Bansal、Angela M. Lam、William Seibel、Sandra Neilson、Phillip A. Furman、Michael J. Sofia
DOI:10.1021/jm4012643
日期:2014.3.13
HTS screening identified compound 2a (piper-azinone derivative) as a low micromolar HCV genotype 1 (GT-1) inhibitor. Resistance mapping studies suggested that this piperazinone chemotype targets the HCV nonstructural protein NS4B. Extensive SAR studies were performed around 2a and the amide function and the C-3/C-6 cis stereochemistry of the piperazinone core were essential for HCV activity. A 10-fold increase in GT-1 potency was observed when the chiral phenylcyclopropyl amide side chain of 2a was replaced with p-fluorophenylisoxazole-carbonyl moiety (67). Replacing the C-6 nonpolar hydrophobic moiety of 67 with a phenyl moiety (95) did not diminish the GT-1 potency. A heterocyclic thiophene moiety (103) and an isoxazole moiety (108) were incorporated as isosteric replacements for the C-6 phenyl moiety (95), resulting in significant improvement in GT-1b and la potency. However, the piperazonone class of compounds lacks GT-2 activity and, consequently, were not pursued further into development.
Solid-phase synthesis and screening of N-acylated polyamine (NAPA) combinatorial libraries for protein binding
作者:Jaclyn A. Iera、Lisa M. Miller Jenkins、Hiroshi Kajiyama、Jeffrey B. Kopp、Daniel H. Appella
DOI:10.1016/j.bmcl.2010.09.054
日期:2010.11
Inhibitors for protein-protein interactions are challenging to design, in part due to the unique and complex architectures of each protein's interaction domain. Most approaches to develop inhibitors for these interactions rely on rational design, which requires prior structural knowledge of the target and its ligands. In the absence of structural information, a combinatorial approach may be the best alternative to finding inhibitors of a protein-protein interaction. Current chemical libraries, however, consist mostly of molecules designed to inhibit enzymes. In this manuscript, we report the synthesis and screening of a library based on an N-acylated polyamine (NAPA) scaffold that we designed to have specific molecular features necessary to inhibit protein-protein interactions. Screens of the library identified a member with favorable binding properties to the HIV viral protein R (Vpr), a regulatory protein from HIV, that is involved in numerous interactions with other proteins critical for viral replication. Published by Elsevier Ltd.