Synthesis and evaluation of c-9 modified N-acetylneuraminic acid derivatives as substrates for N-acetylneuraminic acid aldolase

Several C-9 modified N-acetylneuraminic acid derivatives have been synthesi sed and evaluated as substrates of N-acetylneuraminic acid aldolase. Simple C-9 acyl or ether modified derivatives of N-acetylneuraminic acid were fou nd to be accepted as substrates by the enzyme, albeit being transformed mor e slowly than Neu5Ac itself. H-1 NMR spectroscopy was used to evaluate the extent of the enzyme catalysed transformation of these compounds. Interesti ngly, the chain-extended Neu5Ac derivative 16 is not a substrate for N-acet ylneuraminate lyase and behaves as an inhibitor of the enzyme. (C) 2000 Els evier Science Ltd. All rights reserved.