A facile synthetic route to the natural products suffrutines A (1a), B (1b) and their N-fused analogues (2a and 2b) has been accomplished starting from pyrrole in 8 steps. Their structures were elucidated by a series of NMR spectra and single crystal X-ray crystallography. The in situ¹H NMR monitoring experiments showed the interconversion properties of the four isomers of suffrutines and their stability order 1a (E, E) > 1b (Z, E) > 1d (Z, Z) > 1c (E, Z) in the solution state under ambient conditions. DFT calculations further confirmed the tautomerization results. The preliminary biological test results showed that 1′-aza-suffrutines B (2b) was the most potent in cytotoxic study (MCF-7, IC₅₀ = 7.31 μM), while 1′-aza-suffrutines A (2a) was the most active in a 14-day colony formation assay. In addition, 2a was proved to be a cancer cell apoptosis inducer in annexin V-FITC/PI dual staining tests.

中文翻译：

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A，B及其氮融合类似物的合成及生物学评价

从吡咯开始，从8个步骤开始，已经完成了一种简便的合成途径，可用于合成天然产物Suffrutines A（1a），B（1b）及其N融合类似物（2a和2b）。通过一系列的NMR光谱和单晶X射线晶体学阐明了它们的结构。在原位^1个1 H NMR监测实验表明suffrutines的四种异构体的互变的属性和它们的稳定性为了1A（ê，ê）> 1B（Ž，ê）> 1D（Ž，Ž）> 1C（E，Z）在环境条件下处于溶液状态。DFT计算进一步证实了互变异构化结果。初步的生物学测试结果表明，在细胞毒性研究中，1'-氮杂suffrutines B（2b）最有效（MCF-7，IC ₅₀ = 7.31μM），而1'-氮杂suffrutines A（2a）最为有效。在14天的菌落形成试验中具有活性。另外，在膜联蛋白V-FITC / PI双重染色测试中证明2a是癌细胞凋亡诱导剂。