Degradation of cytidine 5 '-monophospho-N-acetylneuraminic acid under different conditions

The chemical behaviour of cytidine 5'-monophospho-N-acetylneuraminic acid ( CMP-Neu5Ac) under different conditions was studied. We found that the stabi lity of this sugar nucleotide in water and cacodylate buffer was high and s imilar in both systems, although it was more stable in ethanol/water. Hydro lysis rates increased with temperature. 2-Deoxy-2,3-dehydro-N-acetylneurami nic acid (NeuAc2en) was formed in the first few minutes of the treatments. CMP-Neu5Ac was more stable in alkaline (pH 8 and 10) than in acidic (pH 3 a nd 5) conditions; its stability was very similar in neutral (water and etha nol/water) and alkaline conditions. The yield of Neu5Ac2en increased with p H and temperature. Additionally, CMP-Neu5Ac dissolved in the solvent system n-butanol/n-propanol/0.1 N HCl (pH 1) was hydrolyzed very fast (98-99% aft er 1 min). Moreover, this sugar nucleotide dissolved in water or cacodylate buffer (pH 5.8) and when subjected to successive freezing and thawing cycl es did not show any increase in the hydrolysis rate. Finally, no decomposit ion of N-acetylneuraminic acid (Neu5Ac) or Neu5Ac2en was observed under the above-mentioned conditions (pH, temperature, freeze-thaw cycles). (C) 1999 Elsevier Science Inc. All rights reserved.