†Center of Excellence for Innovation in Drug Design and Discovery, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudhya Road, Bangkok 10400, Thailand.
‡Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0650, United States.
ACS Chem Neurosci. 2015 Aug 19;6(8):1317-30. doi: 10.1021/acschemneuro.5b00058. Epub 2015 May 15.
Three series of substituted anti-1,2,3-triazoles (IND, PPRD, and QND), synthesized by cycloaddition from azide and alkyne building blocks, were designed to enhance selectivity and potency profiles of a lead α7 nicotinic acetylcholine receptor (α7-nAChR) agonist, TTIn-1. Designed compounds were synthesized and screened for affinity by a radioligand binding assay. Their functional characterization as agonists and antagonists was performed by fluorescence resonance energy transfer assay using cell lines expressing transfected cDNAs, α7-nAChRs, α4β2-nAChRs, and 5HT3A receptors, and a fluorescence cell reporter. In the IND series, a tropane ring of TTIn-1, substituted at N1, was replaced by mono- and bicyclic amines to vary length and conformational flexibility of a carbon linker between nitrogen atom and N1 of the triazole. Compounds with a two-carbon atom linker optimized binding with Kd's at the submicromolar level. Further modification at the hydrophobic indole of TTIn-1 was made in PPRD and QND series by fixing the amine center with the highest affinity building blocks in the IND series. Compounds from IND and PPRD series are selective as agonists for the α7-nAChRs over α4β2-nAChRs and 5HT3A receptors. Lead compounds in the three series have EC50's between 28 and 260 nM. Based on the EC50, affinity, and selectivity determined from the binding and cellular responses, two of the leads have been advanced to behavioral studies described in the companion article (DOI: 10.1021/acschemneuro.5b00059).
三系列取代的反-1,2,3-三唑（IND、PPRD 和 QND），通过叠氮化物和炔烃构建块的加成反应合成，旨在增强先导α7 烟碱型乙酰胆碱受体（α7-nAChR）激动剂 TTIn-1 的选择性和效力谱。设计的化合物通过放射性配体结合测定法进行亲和力筛选。它们作为激动剂和拮抗剂的功能特征通过使用表达转染 cDNA 的细胞系、α7-nAChRs、α4β2-nAChRs 和 5HT3A 受体以及荧光细胞报告进行荧光共振能量转移测定来进行。在 IND 系列中，TTIn-1 的托烷环取代为单环和二环胺，以改变氮原子和三唑的 N1 之间碳连接体的长度和构象灵活性。具有两个碳原子连接体的化合物优化了结合，其 Kd 值处于亚微摩尔水平。在 PPRD 和 QND 系列中，通过用在 IND 系列中具有最高亲和力构建块固定 TTIn-1 的吲哚的疏水性部分进行了进一步修饰。IND 和 PPRD 系列的化合物作为α7-nAChRs 的激动剂是选择性的，而不是α4β2-nAChRs 和 5HT3A 受体。三个系列中的先导化合物的 EC50 在 28 和 260 nM 之间。基于结合和细胞反应确定的 EC50、亲和力和选择性，两个先导化合物已被推进到同伴文章中描述的行为研究中（DOI：10.1021/acschemneuro.5b00059）。
