Biosynthesis of acaterin:: Incorporation of glycerol into the C3 branched unit

The biosynthesis of the lactone moiety of acaterin was studied using Pseudomonas sp. A92. Feeding experiment with (2R S)-[1-C-13]glycerol revealed that glycerol is efficiently incorporated into the branched three-carbon unit (C-3, C-4 and C-5 positions) of acaterin and its precursor, 4,5-didehydroacaterin. Further feeding studies of (2RS)-[1,1-H-2(2)]- and sn-[3,3-H-2(2)]-glycerols showed that two hydrogens at the sn-C-3 position of glycerol are incorporated into the C-5 position of the two compounds, whereas those at the sn-C-1 position are completely lost during the transformation. These results suggest that acaterin is biosynthesized via a tetronic acid type intermediate. (C) 1998 Elsevier Science Ltd. All rights reserved.