Abstract:
The decomposition of l-¹³C-D-glucose, 6-¹³C-D-glucose, and 1-¹³C-sodium lactate has been studied
in hot (145 ± 3°C) alkaline (3.5 M) sodium hydroxide solution in order to understand the
mechanisms of carbon exchange in the alkaline degradation of glucose. The results show that in
the formation of lactate from glucose the carboxylate (COO¯) carbon is formed preferentially from
Cl carbons but methyl (CH₃) carbon is formed preferentially from C6 carbons. However, on further
decomposition of lactate to ethanol and carbonate, ¹³C-labeled carboxylate (COO¯) is scrambled
equally among carbonate and both carbons in product ethanol molecules. In the production of
glycolate, the labeled Cl carbon mainly ends up as carboxylate (COO¯) carbon, while for C6-labeled
glucose the labeled carbon mainly ends up as alcoholic (CH₂OH) carbon. In the production of acetate
and formate there is also discrimination between Cl and C6 label.
