Protein tyrosine phosphatase 1B (PTP1B) is a well-validated target in therapeutic interventions for type 2 diabetes mellitus (T2DM), however, PTP1B inhibitors containing negatively charged nonhydrolyzable pTyr mimetics are difficult to convert to the corresponding in vivo efficacy owing to poor cell permeability and oral bioavailability. In this work, molecules bearing less acidic heterocycle 2,4-thiazolidinedione and hydantoin were designed, synthesized and evaluated for PTP1B inhibitory potency, selectivity and in vivo antidiabetic efficacy. Among them, compound 5a was identified as a potent PTP1B inhibitor (IC₅₀ = 0.86 μM) with 5-fold selectivity over the highly homologous TCPTP. Long-term oral administration of 5a at a dose of 50 mg/kg not only significantly reduced blood glucose levels, triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) levels but also ameliorated insulin sensitivity in diabetic BKS db mice. Moreover, 5a enhanced the insulin-stimulated phosphorylation of IRβ, IRS-1 and Akt in C2C12 myotubes. A histopathological evaluation of liver and pancreas demonstrated that 5a increased liver glycogen storage and improved islet architecture with more β-cells and fewer α-cells in diabetic mice. Thus, our work demonstrated that compound 5a could serve as a lead compound for the discovery of new antidiabetic drugs.

蛋白酪氨酸磷酸酶 1B (PTP1B) 是 2 型糖尿病 (T2DM) 治疗干预中经过充分验证的靶标，但是，由于细胞通透性差，含有带负电荷的不可水解 pTyr 模拟物的 PTP1B 抑制剂难以转化为相应的体内功效和口服生物利用度。在这项工作中，设计、合成了带有较低酸性杂环 2,4-噻唑烷二酮和乙内酰脲的分子，并评估了 PTP1B 抑制效力、选择性和体内抗糖尿病功效。其中，化合物5a被鉴定为有效的 PTP1B 抑制剂（IC ₅₀  = 0.86 μM），选择性是高度同源的 TCPTP 的 5 倍。长期口服5a50 mg/kg 的剂量不仅显着降低了血糖水平、甘油三酯 (TG) 和低密度脂蛋白胆固醇 (LDL-C) 水平，而且还改善了糖尿病 BKS db 小鼠的胰岛素敏感性。此外，5a增强了胰岛素刺激的 C2C12 肌管中 IRβ、IRS-1 和 Akt 的磷酸化。肝脏和胰腺的组织病理学评估表明，5a增加了肝糖原储存并改善了胰岛结构，在糖尿病小鼠中具有更多的 β 细胞和更少的 α 细胞。因此，我们的工作证明化合物5a可以作为发现新抗糖尿病药物的先导化合物。