Aldolase Catalyzed Reaction for Carbohydrate Synthesis

Aldolase which catalyzes aldol cleavage in the process of glycolysis also catalyzes reverse reaction, aldol condensation, to afford carbohydrates. From this point of view, aldolases are useful catalysts to synthesize novel carbohydrates. The substrate specificity for the enolate source of aldolase catalyzed reactions is very high, but, the enzymes accept many kinds of aldehyde as acceptor substrates of aldol condensation. FDPaldolase whose enolate source is dihydroxyacetone phosphate and sialic acid aldolase whose enolate source is pyruvate are purchased cheaply and many papers on the syntheses of carbohydrates using these aldolases have been published during the last ten years. Especially, the method of synthesizing fluorosugars and azasugars from aldehydes including fluoro or azido group by using aldolases has been well established. It is needless to say that the aldol condensation catalyzed by aldolases is stereospecific and the optical purities of the condensed products are extremely high. Details of the application of the aldolase catalyzed reactions for carbohydrate synthesis will be shown below.