6o08

Publication Abstract from PubMed

Photoexcitation is a common strategy for initiating radical reactions in chemical synthesis. We found that photoexcitation of flavin-dependent "ene"-reductases changes their catalytic function, enabling these enzymes to promote an asymmetric radical cyclization. This reactivity enables the construction of five-, six-, seven-, and eight-membered lactams with stereochemical preference conferred by the enzyme active site. After formation of a prochiral radical, the enzyme guides the delivery of a hydrogen atom from flavin-a challenging feat for small-molecule chemical reagents. The initial electron transfer occurs through direct excitation of an electron donor-acceptor complex that forms between the substrate and the reduced flavin cofactor within the enzyme active site. Photoexcitation of promiscuous flavoenzymes has thus furnished a previously unknown biocatalytic reaction.

Photoexcitation of flavoenzymes enables a stereoselective radical cyclization.,Biegasiewicz KF, Cooper SJ, Gao X, Oblinsky DG, Kim JH, Garfinkle SE, Joyce LA, Sandoval BA, Scholes GD, Hyster TK Science. 2019 Jun 21;364(6446):1166-1169. doi: 10.1126/science.aaw1143. PMID:31221855^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.