AbstractInspired by our previous finding that disesquiterpenoids showed more potent antihepatoma cytotoxicity than their corresponding parent monomers, natural product‐like guaianolide‐germacranolide heterodimers were designed and synthesized from guaianolide diene and germacranolides via a biomimetic Diels–Alder reaction to provide three antihepatoma active dimers with novel scaffolds. To explore the structure–activity relationship, 31 derivatives containing ester, carbamate, ether, urea, amide, and triazole functional groups at C‐14′ were synthesized and evaluated for their cytotoxic activities against HepG2, Huh7, and SK‐Hep‐1 cell lines. Among them, 25 compounds were more potent than sorafenib against HepG2 cells, 15 compounds were stronger than sorafenib against Huh7 cells, and 17 compounds were stronger than sorafenib against SK‐Hep‐1 cells. Compound 23 showed the most potent cytotoxicity against three hepatoma cell lines with IC50 values of 4.4 µM (HepG2), 3.7 µM (Huh7), and 3.1 µM (SK‐Hep‐1), which were 2.7‐, 2.2‐, and 2.8‐fold more potent than sorafenib, respectively. The underlying mechanism study demonstrated that compound 23 could induce cell apoptosis, prevent cell migration and invasion, cause G2/M phase arrest in SK‐Hep‐1 cells. Network pharmacology analyses predicted PDGFRA was one of the potential targets of compound 23, and surface plasmon resonance (SPR) assay verified that 23 had strong affinity with PDGFRA with a dissociatin constant (KD) value of 90.2 nM. These promising findings revealed that structurally novel guaianolide‐germacranolide heterodimers might provide a new inspiration for the discovery of antihepatoma agents.
摘要受二萜类化合物比其相应母体单体具有更强的抗肝癌细胞毒性这一发现的启发,我们设计并通过仿生 Diels-Alder 反应合成了类似天然产物的愈创木酚内酯-愈创木酚内酯异二聚体,提供了三种具有新型支架的抗肝癌活性二聚体。为了探索结构-活性关系,合成了 31 种在 C-14′ 位含有酯、氨基甲酸酯、醚、脲、酰胺和三唑官能团的衍生物,并评估了它们对 HepG2、Huh7 和 SK-Hep-1 细胞系的细胞毒活性。其中,25 个化合物对 HepG2 细胞的作用强于索拉非尼,15 个化合物对 Huh7 细胞的作用强于索拉非尼,17 个化合物对 SK-Hep-1 细胞的作用强于索拉非尼。化合物 23 对三种肝癌细胞株的细胞毒性最强,IC50 值分别为 4.4 µM(HepG2)、3.7 µM(Huh7)和 3.1 µM(SK-Hep-1),分别是索拉非尼的 2.7 倍、2.2 倍和 2.8 倍。基本机制研究表明,化合物23能诱导细胞凋亡,阻止细胞迁移和侵袭,并导致SK-Hep-1细胞G2/M期停滞。网络药理学分析预测 PDGFRA 是化合物 23 的潜在靶点之一,表面等离子体共振(SPR)测定验证了 23 与 PDGFRA 具有很强的亲和力,其解离常数(KD)值为 90.2 nM。这些令人鼓舞的研究结果表明,结构新颖的胍内酯-锗内酯异二聚体可能为发现抗肝癌药物提供新的灵感。