Asymmetric Bioreduction of Activated C=C Bonds Using Zymomonas mobilis NCR Enoate Reductase and Old Yellow Enzymes OYE 1–3 from Yeasts (Eur. J. Org. Chem. 9/2008)

The cover picture shows a culture of yeast cells, whose flavin-dependent reductases – their three-dimensional structure is depicted in the magnifying glass – catalyse the asymmetric bioreduction of C=C bonds. Although these enzymes have been identified already in 1932, their true physiological role remains largely a mystery. Thanks to advances in genetic engineering, these biocatalysts are now becoming available in sufficient amounts to allow their application for preparative-scale biotransformations: Although their “natural” substrates are still unknown, the study of K. Faber et al. on p. 1511 ff shows that they accept an astonishing variety of alkenes bearing an electron-withdrawing group – such as a enals, enones, α,β-unsaturated imides, or nitroalkenes – to furnish the corresponding alkanes with excellent stereoselectivities. S. Kohlwein and G. Oberdorfer are thanked for their contribution in the design of the graphic.