Based on the X-ray crystallography of recombinant BACE1 and a hydroxyethylamine-type peptidic inhibitor, we introduced a cross-linked structure between the P1 and P3 side chains of the inhibitor to enhance its inhibitory activity. The P1 and P3 fragments bearing terminal alkenes were synthesized, and a ring-closing metathesis of these alkenes was used to construct the cross-linked structure. Evaluation of ring size using P1 and P3 fragments with various side chain lengths revealed that 13-membered rings were optimal, although their activity was reduced compared to that of the parent compound. Furthermore, the optimal ring structure was found to be a macrocycle with a dimethyl branched substituent at the P3 β-position, which was approximately 100-fold more active than the non-substituted macrocycle. In addition, the introduction of a 4-carboxymethylphenyl group at the P1′ position further improved the activity.

基于重组 BACE1 和羟乙胺型肽抑制剂的 X 射线晶体学，我们在抑制剂的 P1 和 P3 侧链之间引入了交联结构，以增强其抑制活性。合成了带有末端烯烃的P1和P3片段，并使用这些烯烃的闭环复分解来构建交联结构。使用具有不同侧链长度的 P1 和 P3 片段评估环大小表明，13 元环是最佳的，尽管它们的活性与母体化合物相比有所降低。此外，发现最佳环结构是在 P3 β 位具有二甲基支链取代基的大环，其活性比未取代的大环高约 100 倍。此外，