Isotope labeled sugars synthesis

The resolution of racemic mixtures by amino acid oxidases also forms an important step in the synthesis of isotope labeled sugars and amino acids [259]. 

Starch synthesis is closely related to sucrose synthesis (see Chapters IX and XII). Experiments with isotopically labeled sugars have shown that leaves can form starch from externally supplied glucose, fructose, and sucrose, as well as from several other compounds. Starch is also formed from carbon dioxide during photosynthesis. It was found (78) that when labeled carbon dioxide was fed to leaves, the starch became labeled before the free sugars. Labeled glucose and glucose 1-phosphate did not contribute an... 

Aldolases - Aldolases catalyze reversible aldol condensations of su-gars. A well-studied enzyme is fructose-1,6-dlphosphate aldolase from rabbit muscle. This enzyme exhibits a high specificity for dihydroxy-acetone phosphate as the nucleophile, but tolerates a range of aldehydes as electrophiles (Scheme II).This broad specificity allows synthesis of sugars such as 6-deoxyfructose and Isotopically labeled glucose... 

The preparation of sugars containing isotopic carbon, either uniformly distributed or in specific positions of the carbon chain, is a comparatively recent development in carbohydrate synthesis. Certain of the known synthetic methods have been applied for isotopic labeling and, in addition, certain new synthetic methods have been developed solely for the introduction of the isotope. 

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