Tyrosyl-DNA phosphodiesterase 2 (TDP2) repairs topoisomerase II (TOP2) mediated DNA damages and causes cellular resistance to clinically used TOP2 poisons. Inhibiting TDP2 can potentially sensitize cancer cells toward TOP2 poisons. Commercial compound P10A10, to which the structure was assigned as 7-phenyl triazolopyrimidine analogue 6a, was previously identified as a TDP2 inhibitor hit in our virtual and fluorescence-based biochemical screening campaign. We report herein that the hit validation through resynthesis and structure elucidation revealed the correct structure of P10A10 (Chembridge ID 7236827) to be the 5-phenyl triazolopyrimidine regioisomer 7a. Subsequent structure-activity relationship (SAR) via the synthesis of a total of 47 analogues of both the 5-phenyl triazolopyrimidine scaffold (7) and its bioisosteric triazolopyridine scaffold (17) identified four derivatives (7a, 17a, 17e, and 17z) with significant TDP2 inhibition (IC50 < 50 µM), with 17z showing excellent cell permeability and no cytotoxicity.

中文翻译：

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三唑并嘧啶和三唑并吡啶骨架作为TDP2抑制剂。

酪氨酰-DNA磷酸二酯酶2（TDP2）修复拓扑异构酶II（TOP2）介导的DNA损伤，并引起细胞对临床使用的TOP2毒物的耐药性。抑制TDP2可能会使癌细胞对TOP2毒物敏感。商业化合物P10A10（其结构被指定为7-苯基三唑并嘧啶类似物6a）先前在我们基于虚拟和荧光的生化筛选活动中被鉴定为TDP2抑制剂。我们在本文中报道，通过再合成和结构阐明的命中验证揭示了P10A10的正确结构（Chembridge ID 7236827）为5-苯基三唑并嘧啶区域异构体7a。