XVI International Botanical Congess

Incorporation of 13C labeled acetate or glucose into the isoprenoids from bacteria, algae and plants allowed the detection of a vmvalonate independent route to isoprenoids. Glyceraldehyde 3-phosphate and pyruvate are the first prescursors, yielding by de-carboxylation and condensation 1-deoxy-d-xylulose 5-phosphate. A subsequent rearrangement followed by a reduction yields 2-C-methyl-D-erythrotol 4-phosphate. Labeling experiments with 13C derived in Corynebacterium ammoniagenes from the same non-mevalonate route. Deuterium labeled isotopomers of methylerythritol were synthesized. They were incorporated by Escherichia coli into the prenyl chains of ubiquinone and menaquinone, shedding for the first time light on the precursor role of methylerythritol for isoprenoids. These experiments yielded in addition interesting clues on the fate of hydrogen atoms during the formation of isoprenic units.