2,3-Diarylimidazo[1,2-a]pyridines as potential inhibitors of UV-induced keratinocytes apoptosis: synthesis, pharmacological properties and interactions with model membranes and oligonucleotides by NMR
摘要:
Four 2,3-diarylimidazo[1,2-alpha]pyridines (I, 1a-c) were synthesized as inhibitors of UV-induced apoptosis and showed quite different properties. First, only the pyridinyl derivative I showed protection in molt cells. From the supposed intracellular target, phospholipid membrane models were studied by H-1, H-2 and P-31 NMR spectroscopy. All these molecules can incorporate the membrane bilayer of small unilamellar vesicles of lecithin (SUV). However, I is clearly closed to the external polar head of the lipids, and is relatively mobile in the layer. Conversely, the other molecules are strongly immobilized in the deep part of the external layer. P-31 solid-state NMR spectra recorded on phospholipid dispersions (multilayers vesicles (MLV)) completely excluded any detergent effect or any modification of temperature transition. The only structural or dynamic effect observed was a homogeneous, but limited, reduction in the chemical shift anisotropy in the presence of 1, in agreement with its superficial location. H-2 NMR experiment performed on the same model using perdeuterated phospholipids showed no significant fluidity reduction at the level of terminal CD3 groups in the presence of la-c, according to their deep location. Finaly, their interactions with synthetic oligonucleotide, d(CGATCG)(2) was studied showing non specific interactions of la on the external GC pair, while no interaction was observed with the other derivatives. (C) 2004 Elsevier B.V. All rights reserved.
Metal-free C–H arylation of imidazoheterocycles with aryl hydrazines
作者:Sourav Jana、Sadhanendu Samanta、Avik K. Bagdi、Valerii Z. Shirinian、Alakananda Hajra
DOI:10.1039/c8ra01474d
日期:——
A simple and efficient metal-freearylation of imidazo[1,2-a]pyridines at the C-3 position with arylhydrazine has been achieved at room temperature under ambient air conditions. Various 2,3-disubstituted imidazopyridines and imidazothiazoles were synthesized with high yields. The present methodology demonstrates the usefulness of commercially available aryl hydrazine as an arylating agent.
在室温和环境空气条件下,已经实现了在 C-3 位的咪唑并[1,2- a ]吡啶与芳基肼的简单有效的无金属芳基化。以高产率合成了各种 2,3-二取代的咪唑并吡啶和咪唑噻唑。本方法证明了可商购的芳基肼作为芳基化剂的有用性。