FORMATION AND IDENTIFICATION OF TWO NOVEL ANHYDRO COMPOUNDS OBTAINED BY METHANOLYSIS OF N-ACETYLNEURAMINIC ACID AND CARBOXYL-REDUCED, MENINGOCOCCAL B POLYSACCHARIDE

Article abstract of DOI:10.1016/S0008-6215(00)80538-8

Methanolysis of N-acetylneuraminic acid gives, in addition to the methyl ester methyl β-ketoside, 10-15percent of a product identified by g.l.c.-m.s. as methyl 5-acetamido-2,7-anhydro-3,5-dideoxy-α-D-glycero-D-galacto-nonulopyranosonate (3).Only the major product was formed on methanolysis of the capsular, sialic acid polysaccharides from Neisseria meningitidis serogroup B and C and Escherichia coli K1 (colominic acid).Methanolysis of carboxyl-reduced, meningococcal B polysaccharide affords a major product, identified by g.l.c.-m.s. as methyl 5-acetamido-1,7-anhydro-3,5-dideoxy-β-D-glycero-D-galacto-nonulopyranoside (7).Mass-spectral data for 3 and 7 together with those of known sialic acid derivatives correlate well with previously observed fragmentation patterns.