Optimizing the control of apoptosis by amide/triazole isosteric substitution in a constrained peptoid
摘要:
Apoptosis is a biological process relevant to several human diseases that is strongly regulated through protein-protein complex formation. We have previously reported a peptidomimetic compound as potent apoptotic modulator. Structural studies of this compound showed the presence of cis/trans isomers of the exocyclic tertiary amide bond in slow exchange. This information encouraged us to perform an isosteric replacement of the amide bond by a 1,2,3-triazole moiety, where different substitution patterns would mimic different amide rotamers. The syntheses of these restricted analogs have been carried out using the Ugi multicomponent reaction followed by an intramolecular cyclization. Unexpectedly, for one of the proposed structures, a novel beta -lactam compound was formed. All compounds showed to efficiently inhibit apoptosis, in vitro and in cellular extracts, with slight differences for the corresponding regioisomers. We propose the binding to Apaf-1 as the inhibition mechanism. (c) 2013 Elsevier Masson SAS. All rights reserved.
15N NMR spectroscopic and theoretical GIAO-DFT studies for the unambiguous characterization of disubstituted 1,2,3-triazoles
作者:Miriam Corredor、Jordi Bujons、Àngel Messeguer、Ignacio Alfonso
DOI:10.1039/c3ob41587b
日期:——
an easy task, and the development of robust characterization methodologies is needed. Herein, the three possible isomeric forms of disubstituted 1,2,3-triazole (1,4- or 1,5- or 2,4-disubstituted derivatives) have been characterized and distinguished by routine 1H/15N gHMBC experiments at 15N natural abundance. The calculated (GIAO-B3LYP/6-311++G**) 15NNMR chemical shifts showed good agreement with
作为结构支架,1,2,3-三唑环最近引起了新的兴趣,在不同领域中有许多应用。但是,正确地分配正确的结构常常不是一件容易的事,因此需要开发可靠的表征方法。本文中,已通过常规的1 H / 15 N gHMBC实验(在15 ℃下)对三取代的1,2,3-三唑(1,4-或1,5-或2,4-二取代的衍生物)的三种可能的异构体形式进行了表征和区分。N自然丰度。计算得出的(GIAO-B3LYP / 6-311 ++ G **)15 N NMR化学位移与实验值显示出很好的一致性,进一步支持了其明确的结构表征。