Pyruvate dehydrogenase kinases (PDKs) are widely over-expressed in various human solid cancers, making them attractive therapeutic targets for cancer treatment. Herein, we report the identification of structurally novel PDKs inhibitors by screening of an in-house small molecule library. Biochemical assay indicated that the identified compounds 1–4 inhibited PDK1 activity with EC₅₀ values of 0.50, 1.99, 4.64, and 0.42 µM, respectively. The ITC analysis suggested that the identified compounds 1–4 were pan-isoform PDK inhibitors, which bound to and inhibited the four PDK isoforms. Moreover, 1–4 dose-dependently reduced pyruvate dehydrogenase complex phosphorylation in NCI-H1975 cell. Molecular docking suggested that the most potent compound 4 docked well in the ATP binding pocket of the four PDK isoforms, forming direct hydrogen bond interactions with the conserved amino acids Thr and Asp in ATP binding pocket of PDKs. The cell viability assay demonstrated that 4 potently blocked NCI-H1975 cell proliferation (IC₅₀ = 3.32 µM), but had little effect on human normal lung cell MRC-5 even with the tested concentration up to 40 µM. All the data demonstrated that 4 was a promising lead for the development of structurally novel PDKs inhibitor for the cancer treatment.

丙酮酸脱氢酶激酶（PDK）在各种人类实体癌中广泛表达，使其成为癌症治疗的有吸引力的治疗靶标。本文中，我们报告了通过筛选内部小分子文库鉴定结构新颖的PDK抑制剂的方法。生物化学测定，所识别的化合物所示，1 - 4与EC抑制PDK1活性_50个0.50，1.99，4.64，和0.42μM的值，分别。所述ITC分析表明，鉴定的化合物1 - 4分别为泛PDK同种型的抑制剂，其结合并抑制四个PDK同种型。此外，1 - 4NCI-H1975细胞中剂量依赖性降低的丙酮酸脱氢酶复合物的磷酸化。分子对接表明，最有效的化合物4很好地对接在四个PDK同工型的ATP结合口袋中，与PDK的ATP结合口袋中的保守氨基酸Thr和Asp形成了直接的氢键相互作用。细胞活力测定表明，有4种有效阻断NCI-H1975细胞增殖（IC ₅₀  = 3.32 µM），但即使测试浓度高达40 µM，对人正常肺细胞MRC-5的影响也很小。所有数据表明，4是开发用于癌症治疗的结构新颖的PDKs抑制剂的有希望的先导。