EFFICIENT SYNTHESIS OF SECONDARY CARBOXAMIDES WITH ω-SUBSTITUTED ETHYL AND PROPYL GROUPS ON NITROGEN ATOM BY NUCLEOPHILIC RING OPENING OF CYCLIC IMIDATES
An efficient synthesis of secondary carboxamides carrying ω-substituted ethyl and propyl groups on nitrogen atom has been developed which highlights nucleophilic ring opening of 2-methyl-2-oxazoline, 2-methyl-2-oxazine, and their derivatives with (CH3)3SiX and HX (X= Cl, N3, SeC6H5, SC6H5) type reagents.
4-Alkyloxyimino-cytosine nucleotides: tethering approaches to molecular probes for the P2Y6 receptor
作者:P. Suresh Jayasekara、Matthew O. Barrett、Christopher B. Ball、Kyle A. Brown、Eszter Kozma、Stefano Costanzi、Lucia Squarcialupi、Ramachandran Balasubramanian、Hiroshi Maruoka、Kenneth A. Jacobson
DOI:10.1039/c3md00132f
日期:——
4-Alkyloxyimino derivatives of pyrimidine nucleotides display high potency as agonists of certain G protein-coupled P2Y receptors (P2YRs). In an effort to functionalize a P2Y6R agonist for fluorescent labeling, we probed two positions (N4 and γ-phosphate of cytidine derivatives) with various functional groups, including alkynes for click chemistry. Functionalization of extended imino substituents at the 4 position of the pyrimidine nucleobase of CDP preserved P2Y6R potency generally better than γ-phosphoester formation in CTP derivatives. Fluorescent Alexa Fluor 488 conjugate 16 activated the human P2Y6R expressed in 1321N1 human astrocytoma cells with an EC50 of 9 nM, and exhibited high selectivity for this receptor over other uridine nucleotide-activated P2Y receptors. Flow cytometry detected specific labeling with 16 to P2Y6R-expressing but not to wild-type 1321N1 cells. Additionally, confocal microscopy indicated both internalized 16 (t1/2 of 18 min) and surface-bound fluorescence. Known P2Y6R ligands inhibited labeling. Theoretical docking of 16 to a homology model of the P2Y6R predicted electrostatic interactions between the fluorophore and extracellular portion of TM3. Thus, we have identified the N4-benzyloxy group as a structurally permissive site for synthesis of functionalized congeners leading to high affinity molecular probes for studying the P2Y6R.
We designed a combinatorial library of trifunctional scaffold-derived compounds, which were derivatized with 30 different in-house-made azides. The compounds were proposed to mimic insulin receptor (IR)-binding epitopes in the insulin molecule and bind to and activate this receptor. This work has enabled us to test our synthetic and biological methodology and to prove its robustness and reliability
2-Dialkynyl derivatives of (N)-methanocarba nucleosides: ‘Clickable’ A3 adenosine receptor-selective agonists
作者:Dilip K. Tosh、Moshe Chinn、Lena S. Yoo、Dong Wook Kang、Hans Luecke、Zhan-Guo Gao、Kenneth A. Jacobson
DOI:10.1016/j.bmc.2009.12.018
日期:2010.1
nucleoside 5′-uronamides to contain dialkyne groups on an extended adenine C2 substituent, as synthetic intermediates leading to potent and selective A3 adenosine receptor (AR) agonists. The proximal alkyne was intended to promote receptorrecognition, and the distal alkyne reacted with azides to form triazole derivatives (click cycloaddition). Click chemistry was utilized to couple an octadiynyl A3AR
我们修饰了一系列 (N)-methanocarba 核苷 5'-uronamides 以在扩展的腺嘌呤 C2 取代基上包含二炔基团,作为合成中间体,导致有效和选择性的 A 3腺苷受体 (AR) 激动剂。近端炔烃旨在促进受体识别,远端炔烃与叠氮化物反应形成三唑衍生物(点击环加成)。利用点击化学将八炔基 A 3 AR 激动剂偶联到含叠氮基的荧光、化学反应性、生物素化和其他部分,保留与 A 3 AR的选择性结合。引入了双功能硫醇反应性交联剂。最有效和最具选择性的新化合物是 1-金刚烷基衍生物 ( K i6.5 nM),尽管一些点击产品的K i值在 200-400 nM 的范围内。其他有效的选择性衍生物(K i at A 3 AR in nM)被用作可能的受体亲和标记:3-nitro-4-fluorophenyl (10.6), α-bromophenacyl (9.6), 硫醇反应性异噻唑酮 (102)