Chemical and enzymatic methodologies for the synthesis of enantiomerically pure glyceraldehyde 3-phosphates

• d-Glyceraldehyde 3-phosphate (d-GAP) has been synthesized in stable form.
• l-GAP is preferably synthesized by enzymatic phosphorylation of l-glyceraldehyde.
• The pH-dependent stability of GAP has been investigated over time by 1H and 31P NMR.
• GAP has been shown to be stable in acidic aqueous solution below pH 4.
• At pH >4 the GAP-degradation products methylglyoxal and lactic acid were observed.

Glyceraldehyde 3-phosphates are important intermediates of many central metabolic pathways in a large number of living organisms. d-Glyceraldehyde 3-phosphate (d-GAP) is a key intermediate during glycolysis and can as well be found in a variety of other metabolic pathways. The opposite enantiomer, l-glyceraldehyde 3-phosphate (l-GAP), has been found in a few exciting new pathways. Here, improved syntheses of enantiomerically pure glyceraldehyde 3-phosphates are reported. While d-GAP was synthesized by periodate cleavage of d-fructose 6-phosphate, l-GAP was obtained by enzymatic phosphorylation of l-glyceraldehyde. 1H- and 31P NMR spectroscopy was applied in order to examine pH-dependent behavior of GAP over time and to identify potential degradation products. It was found that GAP is stable in acidic aqueous solution below pH 4. At pH 7, methylglyoxal is formed, whereas under alkaline conditions, the formation of lactic acid could be observed.

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