很容易从相应的噻吩基醛中获得的3-(噻吩-2-基)-和3-(噻吩-3-基)烯丙胺可以与各种酸酐和α,β-不饱和酰氯(马来酸,顺丁烯二酸)相互作用,以及苯基马来酸酐,叔丁酰和肉桂酰氯等),导致形成噻吩并[2,3- f ]异吲哚核。通常,反应顺序包括三个连续的步骤:初始烯丙胺的氮原子的酰化,分子内Diels-Alder乙烯基芳烃(IMDAV)反应以及Diels-Alder加合物中二氢噻吩环的最终芳构化。彻底研究了该方法的范围和局限性。借助X射线分析表明,关键步骤IMDAV反应通过exo进行。-过渡态,引起目标杂环的单一非对映异构体的排他形成。在马来酸酐的情况下,该方法允许获得官能取代的噻吩并[2,3- f ]异吲哚羧酸,其对于进一步转化和随后的生物筛选是潜在有用的底物。
Design and synthesis of natural product derivatives with selective and improved cytotoxicity based on a sesquiterpene scaffold
摘要:
Brasilamide E (1) is a bisabolane sesquiterpenoid isolated from the solid-substrate fermentation cultures of a plant endophytic fungus Paraconiothyrium brasiliense. The compound specifically inhibited proliferation of the MCF-7 cells, but did not show cytotoxicity towards the negative controls HaCaT and NIH3T3 cells (IC50 > 50 mu M). To improve its potency while maintain selectivity, a total of 27 derivatives of 1 were designed, synthesized, and evaluated for in vitro cytotoxicity against six tumor cell lines and the negative control NIH3T3 cells. Among these compounds, compound 12b showed significantly improved potency against the MCF-7, HeLa, and HO8910 cells with IC50 values of 0.13-0.25 mu M compared to 1 (IC50 8.47-18.00 mu M), and remained nontoxic to the NIH3T3 cells. (C) 2016 Elsevier Ltd. All rights reserved.