The natural product cepafungin I was recently reported to be one of the most potent covalent inhibitors of the 20S proteasome core particle through a series of in vitro activity assays. Here, we report a short chemoenzymatic total synthesis of cepafungin I featuring the use of a regioselective enzymatic oxidation to prepare a key hydroxylated amino acid building block in a scalable fashion. The strategy developed herein enabled access to a chemoproteomic probe, which in turn revealed the exceptional selectivity and potency of cepafungin I toward the β2 and β5 subunits of the proteasome. Further structure-activity relationship studies suggest the key role of the hydroxyl group in the macrocycle and the identity of the lipid tail in modulating the potency of this natural product family. This study lays the groundwork for further medicinal chemistry exploration to fully realize the anticancer potential of cepafungin I.

最近通过一系列体外研究报道，天然产物头孢芬净I是20S蛋白酶体核心颗粒最有效的共价抑制剂之一。活性测定。在这里，我们报告了头孢芬净 I 的简短化学酶促全合成，其特点是使用区域选择性酶促氧化以可扩展的方式制备关键的羟基化氨基酸构建块。本文开发的策略使得能够使用化学蛋白质组学探针，这反过来揭示了头孢芬净 I 对蛋白酶体 β2 和 β5 亚基的特殊选择性和效力。进一步的构效关系研究表明羟基在大环中的关键作用和脂质尾部在调节该天然产物家族效力方面的特性。本研究为进一步的药物化学探索奠定了基础，以充分发挥头孢芬净 I 的抗癌潜力。