Motoaki Goto

Thermal and photochemical degradation of sodium N-acetylneuraminate

Abstract The thermal and photochemical degradation products of sodium N -acetylneuraminate (sodium Neu5Ac) were investigated by means of 1 H- and 13 C-n.m.r. spectroscopy, and mass spectrometry. Under all thermal conditions, sodium 5-acetamido-4,8-anhydro-3,5-dideoxy- d - glycero - d - galacto -nonulosonate (sodium N -acetyl-4,8-anhydroneuraminate) was obtained as the main product; on heating in alkaline solution, 4-acetamido-3,7-anhydro-2,4-dideoxy- d - glycero - d - galacto -octonic acid, pyrrole-2-carboxylic acid, and sodium 5-( d - arabino -tetrahydroxybutyl)pyrrole-2-carboxylate; on heating in acidic solution, sodium 5-( d - erythro -furanosyl)pyrrole-2-carboxylate and sodium 5-acetamido-2,7-anhydro-3,5-dideoxy- d - glycero -α- d - galacto - nonulopyranosonate (sodium N -acetyl-2,7-anhydroneuraminate); on refluxing in neutral solution, 2-(β- d - erythro -furanosyl)pyrrole; and on heating of sodium Neu5Ac powder, 5-acetamido-2,6-anhydro-3,5-dideoxy- d - glycero - d - galacto -non-2-enonic acid were obtained. Furthermore, on exposure to u.v. light (360 nm), 4-acetamido-2,4-dideoxy- d - glycero - d - galacto -octonic acid was produced.