Pin1 (Protein interaction with never in mitosis A1) is a validated molecular target for anticancer drug discovery. Herein, we reported the design, synthesis, and structure-activity relationship study of novel ring A modified AKBA (3-acetyl-11-keto-boswellic acid) derivatives as Pin1 inhibitors. Most compounds showed superior Pin1 inhibitory activities to AKBA. One of the most promising compounds, 10a, potently inhibited Pin1 with IC₅₀ value of 0.46 μM, while it displayed excellent anti-proliferative effect against prostate cancer cells PC-3 with GI₅₀ value of 1.82 μM. Structure-activity relationship indicated that reasonable structural modifications in ring A had significant impact on improving activity. Further mechanism research revealed that 10a decreased the level of Cyclin D1 and caused cell cycle arrest at G0/G1 phase in PC-3 cancer cells. Thus, compound 10a may serve as potential anti-prostate cancer agent for further investigation through Pin1 inhibition.

Pin1（蛋白质在有丝分裂A1中从未相互作用）是经过验证的抗癌药物分子靶标。在本文中，我们报道了作为Pin1抑制剂的新型A环修饰的AKBA（3-乙酰基-11-酮-乳香酸）衍生物的设计，合成和构效关系研究。大多数化合物显示出优于AKBA的Pin1抑制活性。最有前途的化合物之一10a可以有效地抑制Pin1，其IC ₅₀值为0.46μM，而它对GI ₅₀值为1.82μM的前列腺癌细胞PC-3表现出优异的抗增殖作用。结构-活性关系表明，环A中合理的结构修饰对改善活性具有重要影响。进一步的机理研究表明10a降低了PC-3癌细胞中Cyclin D1的水平并导致细胞周期停滞在G0 / G1期。因此，化合物10a可以作为潜在的抗前列腺癌药物，通过抑制Pin1进行进一步研究。