Aldolases and Ketolases

Short syntheses of L-fucose analogues have been achieved (3 enzymatic steps) by aldol condensation of DHAP with various a-hydroxyaldehyde derivatives (using L-fuculose phosphate aldolase), followed by phosphate hydrolysis (alkaline phosphatase) and subsequent ketol isomerization (L-fucose isomerase). Selective C-labelling of thymidine in all positions of the 2 -deoxyribose ring has been achieved using an aldolase-catalysed reaction with appropriately C-labelled DHAP/acetaldehyde substrates. The labelled sugar was then converted 

Carbohydrate Chemistry, Volume 34 The Royal Society of Chemistry, 2003 

---

The transketolase-catalyzed conversion of xylulose-5-phosphate and ribose-5-phosphate to glyceraldehyde-3-phosphate and sedoheptulose-7-phosphate. Although the aldolase and ketolase reactions superficially resemble each other, they proceed by very different mechanisms. This is because in the aldolase reaction the carbon adjacent to a carbonyl... 

---