The oligomerisation of L-amino acids by papain was studied in a mixer ball mill and in a planetary ball mill. The biocatalyst proved stable under the ball milling conditions providing the corresponding oligopeptides in good to excellent yields and with a variable degree of polymerisation. Both parameters were found to be dependent on the reaction conditions and on the nature of the amino acid (specifically on its side-chain size and hydrophobicity). In addition, the chemoenzymatic oligomerisation was demonstrated by utilising twin-screw extrusion technology, which allowed for a scalable continuous process. Finally, the synthesised oligo(L-Leu) 2b proved to be active as a catalyst in the Juliá–Colonna enantioselective epoxidation of chalcone derivatives.

中文翻译：

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木瓜蛋白酶通过铣削和双螺杆挤出的寡肽机械化学合成：在朱利亚-哥伦娜对映选择性环氧化中的应用

在混合球磨机和行星式球磨机中研究了木瓜蛋白酶对L-氨基酸的低聚。该生物催化剂在球磨条件下被证明是稳定的，以良好至优异的产率和可变的聚合度提供相应的寡肽。发现这两个参数都取决于反应条件和氨基酸的性质（具体取决于其侧链大小和疏水性）。此外，通过利用双螺杆挤出技术展示了化学酶促低聚反应，该技术可实现可扩展的连续过程。最后，合成的寡聚（L -Leu）2b被证明在查尔酮衍生物的Juliá-Colonna对映选择性环氧化中具有催化活性。