5-Hydroxypentane-2,3-dione (laurencione), a bacterial metabolite of 1-deoxy-D-threo-pentulose

Abstract

Cell-free systems from the bacteria Escherichia coli and Klebsiella planticola that were incubated with 13C labeled pyruvate and D-glyceraldehyde synthesized 5-hydroxypentane-2,3-dione (laurencione) along with 1-deoxy-D-threo-pentulose (1-deoxy-D-xylulose). Both compounds showed identical labeling patterns, indicating that the C5 skeletons were derived from the condensation of (hydroxyethyl)thiamin on D-glyceraldehyde. Conversion of [5,5-2H2]deoxyxylulose into laurencione by a cell-free system from E. coli showed that the α-dione is obtained from the pentulose by water elimination.