A series of non-covalent piperidine-containing peptidyl derivatives with various substituents at side chains of different residues were designed, synthesized and evaluated as proteasome inhibitors. After proteasome inhibitory evaluations of all the synthesized target compounds, selected ones were tested for their anti-proliferation activities against three multiple myeloma (MM) cell lines. 8 analogues displayed more potent activities than carfilzomib, and the most promising compound 24 showed IC₅₀ values of 0.8±0.2 nM against 20S proteasome and 8.42±0.74 nM, 7.14±0.52 nM, 14.20±1.08 nM for RPMI 8226, NCI-H929 and MM.1S cell lines, respectively. Additionally, mechanisms of anti-cancer activity of representative compound 24 were further investigated. Apoptosis of RPMI-8226 cells were achieved through accumulating polyubiquitin and inducing the cleavage of caspase and PARP. Besides, half-life in rat plasma of compound 24 was prolonged after optimization, which would be helpful for increasing in vivo activities of this series of derivatives. All the studies confirmed that piperidine-containing non-covalent proteasome inhibitors can be potential leads for anti-MM drug development.

一系列在不同残基的侧链上具有各种取代基的非共价含哌啶肽基衍生物被设计、合成并评估为蛋白酶体抑制剂。在对所有合成的目标化合物进行蛋白酶体抑制评估后，测试所选化合物对三种多发性骨髓瘤 (MM) 细胞系的抗增殖活性。8 种类似物显示出比卡非佐米更有效的活性，最有前途的化合物24对 20S 蛋白酶体的IC ₅₀值为 0.8±0.2 nM，对RPMI 82926 的IC ₅₀值为 8.42±0.74 nM、7.14±0.52 nM、14.20±1.08 nM MM.1S 细胞系，分别。此外，代表性化合物24的抗癌活性机制被进一步调查。RPMI-8226 细胞的凋亡是通过积累多聚泛素和诱导 caspase 和 PARP 的裂解来实现的。此外，优化后化合物24在大鼠血浆中的半衰期延长，这将有助于提高该系列衍生物的体内活性。所有研究证实，含哌啶的非共价蛋白酶体抑制剂可能是抗 MM 药物开发的潜在线索。