6,6-Spiroimine analogs of (−)-gymnodimine A: synthesis and biological evaluation on nicotinic acetylcholine receptors
作者:Leslie Duroure、Thierry Jousseaume、Rómulo Aráoz、Elvina Barré、Pascal Retailleau、Laurent Chabaud、Jordi Molgó、Catherine Guillou
DOI:10.1039/c1ob06257c
日期:——
Simple models of the spiroimine core of (â)-gymnodimine A have been synthesized in racemic and optically active forms. The quaternary carbon of the racemic spiroimines was created by Michael addition of a β-ketoester to acrolein, whereas the asymmetric allylic alkylation of the same β-ketoester was used to access the spiroimines in an enantioselective fashion. Both racemic and enantio-enriched mixtures were tested for their biological activities on Xenopusoocytes either expressing (human α4β2) or having incorporated (Torpedo α12βγδ) nicotinic acetylcholine receptors (nAChRs). These spiroimine analogs of (â)-gymnodimine A inhibited acetylcholine-evoked nicotinic currents, but were less active than the phycotoxin. Our results reveal that the 6,6-spiroimine moiety is important for the blockade of nAChRs and support the hypothesis that it is one of the pharmacophores of this group of toxins.
(α)-gymnodimine A 螺环亚胺核心的简单模型已经以外消旋和旋光形式合成。外消旋螺胺的季碳是通过迈克尔将β-酮酯添加到丙烯醛而产生的,而相同β-酮酯的不对称烯丙基烷基化用于以对映选择性方式获得螺胺。外消旋和对映体富集的混合物都测试了它们对非洲爪蟾细胞的生物活性,无论是表达(人α4β2)还是掺入(鱼雷α12ββ)烟碱乙酰胆碱受体(nAChRs)。这些 (α)-裸二胺 A 的螺胺类似物可抑制乙酰胆碱诱发的烟碱电流,但活性不如藻毒素。我们的结果表明,6,6-螺胺部分对于阻断 nAChR 很重要,并支持它是这组毒素的药效团之一的假设。