ABSTRACT
References .......................................................................................................................... 560
Decarboxylation of malonic acid is a well-known process in the biosynthesis of long-chain
fatty acids starting from acetic acid. If this kind of enzymes exhibits enantioselectivity for asubstituted malonates, it will be useful as a novel method for preparing optically active
carboxylic acids. Indeed malonyl-CoA decarboxylase from uropygial gland is enantioselective
to the substrate and the product. Racemate of methylmalonyl-CoA (1) was incubated with
the above decarboxylase in 3H2O. (S)-Enantiomer was smoothly decarboxylated to result in
2-(3H)-propionyl-CoA (2), while (R)-isomer of the substrate remained intact (Equation 21.1).
The absolute configuration of a-carbon of resulting 2 was revealed to be (R). Thus, the decarboxylase distinguishes the chirality of 1 and gives enantiomerically pure (R)-isomer by
retention of configuration [1].
