Lactams are ubiquitous structural motifs present in numerous natural products and active pharmaceutical ingredients, and they are also recognized as versatile synthons in the preparation of various nylons. Conventional chemical methods for the preparation of monocyclic lactams rely on petrochemical sources, energy intensive processes and often harsh reaction conditions. In recent years, biocatalysis offers an alternative way to synthesize lactam products.

Recently，the SUN Zhoutong group from Tianjin Institute of Industrial Biology, Chinese Academy of Sciences (TIBCAS), has reported an intramolecular cyclization catalyzed by carboxylic acid reductases (CAR) only with the use of ATP to transform amino acids into diverse lactams, including γ-/δ-/ε-lactams and chiral derivatives. The versatility of this CAR-directed intramolecular cyclization was investigated, and the broad substrate acceptance points to its application potential in the biosynthesis of chiral lactams. These results demonstrate that CAR-catalyzed lactamization is a promising approach for the synthesis of chiral lactam compounds under mild conditions, thereby enriching the toolbox for the biosynthesis of lactams as a viable alternative to purely chemical procedures.

This work was supported by the National Key Research and Development Program of China and other programs. The research paper entitled “Carboxylic acid reductases enable intramolecular lactamization reactions” has been published in Green Synthesis & Catalysis. QIN Zongmin, a PhD student at TIBCAS, is the first author of the paper, and professor SUN Zhoutong, and associate professor QU Ge, are co-corresponding authors of the paper.