[1S05e] 13. Microbial Engineering for Natural Products Synthesis - Part 3

6:00 PM - 6:15 PM JST(9:00 AM - 9:15 AM UTC)

[1MENP-18] Biocatalytic Synthesis of a-Hydrazino Acids and Their Incorporation into Macrocyclic Peptide Scaffolds

○Kenichi Matsuda¹, Toshiyuki Wakimoto¹ (1. Hokkaido University (Japan))

Keywords:

Biocatalysis,Chemo-Enzymatic Synthesis,N-N bonds,Cyclic Peptides,Natural Products

The nitrogen–nitrogen (N–N) bond is a prevalent motif in both natural and synthetic organic molecules. In biological systems, cupin metalloenzymes mediate the rearrangement of azanyl esters to generate a-hydrazino acids, which serve as pivotal intermediates en route to a wide array of N–N bond-containing natural products^[1-3]. Despite their biosynthetic significance, the synthetic applications of cupin metalloenzymes remain largely underexplored, owing to the inherent instability of their substrates; azanyl esters. To overcome this limitation, we devised a practical biocatalytic strategy for accessing a-hydrazino acids, wherein the requisite azanyl esters are generated in situ from hydroxyamines and pre-activated amino acids. This platform enabled comprehensive investigations into substrate scope, structure-guided enzyme engineering, and metal dependency, culminating in the biocatalytic preparation of a diverse set of N^a- and/or C^a-mono- and disubstituted a-hydrazino acids. The enzymatically derived a-hydrazino acids were produced on a preparative scale and subsequently elaborated through combinatorial peptide chemistry, then site-selectively macrocyclized by penicillin-binding protein-type thioesterases (PBP-type TEs)^[4-6], thereby establishing a streamlined chemoenzymatic route to cyclic hydrazinopeptides. Notably, the a-hydrazino acid moiety proved to be a versatile reactive handle amenable to late-stage diversification. This work demonstrates the untapped synthetic potential of N–N bond-forming cupin metalloenzymes and provides a robust platform for accessing a-hydrazino acids and their downstream products.