Degradation of chondroitin 4-sulphate by tri-fluoroacetolysis: isolation of oligosaccharides from the carbohydrate-protein linkage region.

Oligosaccharides from the linkage-region tetrasaccharide, beta-D-GlcpA-(1----3)-beta-D-Galp-(1----3)-beta-D-Galp-(1----4)-D- Xylp, of chondroitin 4-sulphate were isolated after trifluoroacetolysis. The oligosaccharides were purified by ion-exchange chromatography and paper chromatography and subjected to sugar and methylation analysis and g.l.c.-m.s. The recovery of linkage-region oligosaccharides was approximately 45% after trifluoroacetolysis, calculated according to the D-xylose present in the chondroitin 4-sulphate preparation. The following structures were identified: beta-D-Galp-(1----4)-D-Xylp, beta-D-Galp-(1----3)-D-Galp, beta-D-Galp-(1----3)-beta-D-Galp-(1----4)-D-Xylp, beta-D-GlcpA-(1----3)-beta-D-Galp-(1----3)-beta-D-Galp-(1----4)-D- Xylp.