G.l.c.-m.s. of partially methylated and acetylated derivatives of L-glycero-D-manno- and D-glycero-D-manno-heptopyranoses and -heptitols.

Methylated or acetylated heptopyranose derivatives were prepared variously from L-glycero-D-manno- and D-glycero-D-manno-heptopyranose, O-L- glycero-alpha-D-manno-heptopyranosyl-(1----3)-L-glycero-D-manno- heptopyranose, O-L-glycero-alpha-D-manno-heptopyranosyl-(1----7)-L-glycero- D-manno-heptopyranose, and O-L-glycero-alpha-D-manno- heptopyranosyl-(1----7)-O-L-glycero-alpha-D-manno- heptopyranosyl-(1----3)-L-glycero-D-manno- heptopyranose, which are structural elements of the heptose region of enterobacterial lipopolysaccharides. Each derivative was investigated by g.l.c. and g.l.c.-m.s., and the retention times and fragmentation patterns were used to identify partial structures of the heptose region of the core oligosaccharide of bacterial LPS.