人类 DNA 拓扑异构酶对于重要的细胞过程至关重要，包括 DNA 复制、转录、染色质浓缩及其结构的维持。癌症治疗中采用的重要策略之一涉及抑制特定类型的拓扑异构酶，称为拓扑异构酶 II (Topo II)。咔唑衍生物因其多种生物活性而受到认可，最近已成为肿瘤学研究的重要焦点。本研究评估了三种对称取代的咔唑衍生物的功效：2,7-二(2-呋喃基)-9H-咔唑 (27a)、3,6-二(2-呋喃基)-9H-咔唑 (36a) 和 3 ,6-二(2-噻吩基)-9H-咔唑(36b) - 作为抗癌剂。在研究的咔唑衍生物中，带有两个呋喃部分的化合物3,6-二(2-呋喃基)-9H-咔唑成为拓扑II的新型催化抑制剂。值得注意的是，3,6-二(2-呋喃基)-9H-咔唑有效选择性地抑制 Topo IIα 的松弛和去连接活性，而对 IIβ 亚型的影响最小。这些发现强调了化合物 3,6-Di(2-呋喃基)-9H-咔唑作为有希望的主要候选药物的潜力，值得在抗癌药物开发领域进行进一步研究。

Human DNA topoisomerases are essential for crucial cellular processes, including DNA replication, transcription, chromatin condensation, and maintenance of its structure. One of the significant strategies employed in cancer treatment involves the inhibition of a specific type of topoisomerase, known as topoisomerase II (Topo II). Carbazole derivatives, recognised for their varied biological activities, have recently become a significant focus in oncological research. This study assesses the efficacy of three symmetrically substituted carbazole derivatives: 2,7-Di(2-furyl)-9H-carbazole (27a), 3,6-Di(2-furyl)-9H-carbazole (36a), and 3,6-Di(2-thienyl)-9H-carbazole (36b) - as anticancer agents. Among investigated carbazole derivatives, compound 3,6-di(2-furyl)-9H-carbazole bearing two furan moieties emerged as a novel catalytic inhibitor of Topo II. Notably, 3,6-di(2-furyl)-9H-carbazole effectively selectively inhibited the relaxation and decatenation activities of Topo IIα, with minimal effects on the IIβ isoform. These findings underscore the potential of compound 3,6-Di(2-furyl)-9H-carbazole as a promising lead candidate warranting further investigation in the realm of anticancer drug development.