Studies of alkaline mediated phosphate migration in synthetic phosphoethanolamine L-glycero-D-manno-heptoside derivatives

Synthetic 2-, 3-, 4- and B-monophosphate derivatives of methyl alpha-D-mann opyranosides, the 4-, 6- and 7-monophosphate derivatives of methyl L-glycer o-alpha-D-manno-heptopyranosides and the corresponding phosphoethanolamine derivatives and a 6,7-cyclic phosphate analogue of methyl L-glycero-alpha-D -manno-heptopyranoside were used to study phosphate migration and hydrolysi s when subjected to strong alkaline conditions (4 M KOH, 120 degrees C, 18 h). The resulting products were analyzed by H-1 NMR spectroscopy and electr ospray mass spectrometry. It was found that phosphate substituents were sta ble under these conditions and neither migration nor hydrolysis was observe d except for the heptose 7-phosphate, which gave a substantial amount of ph osphate hydrolysis. In phosphoethanolamine-substituted compounds migration to adjacent positions with concomitant loss of ethanolamine was found toget her with hydrolysis. (C) 1998 Elsevier Science Ltd. All rights reserved.