BIOSYNTHESIS OF ACATERIN - INCORPORATION OF GLYCEROL INTO THE C-3 BRANCHED UNIT

The biosynthesis of the lactone moiety of acaterin was studied using P seudomonas sp. A92. Feeding experiment with (2R S)-[1-C-13]glycerol re vealed that glycerol is efficiently incorporated into the branched thr ee-carbon unit (C-3, C-4 and C-5 positions) of acaterin and its precur sor, 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 th e two compounds, whereas those at the sn-C-1 position are completely l ost during the transformation. These results suggest that acaterin is biosynthesized via a tetronic acid type intermediate. (C) 1998 Elsevie r Science Ltd. All rights reserved.