IMPROVED PROTOCOL FOR THE FORMATION OF N-(P-NITROBENZYLOXY)AMINOALDITOL DERIVATIVES OF OLIGOSACCHARIDES

An improved procedure has been developed for the rapid derivatization of oligosaccharides with W-detectable p-nitrobenzylhydroxylamine (PNB) . The improved conditions used result in quantitative derivatization o f neutral oligosaccharides. Sialylated oligosaccharides can also be qu antitatively PNB-derivatized without detectable desialylation. Of the oligosaccharides tested, only the derivatization of oligogalactosyluro nic acids was incomplete (yield similar to 70%). PNB-derivatization of tamarind seed xyloglucan oligosacccharides results in products with i mproved chromatographic properties during HPAEC, These PNB derivatives were also subjected to hydrophilic interaction chromatography (HILIC) and analyzed by on-line LC-MS. On-line LC-MS is readily usable with H ILIC, as this chromatographic technique does not require salt-containi ng solvents. Approximately 10 pmol of a PNB-derivatized oligosaccharid e can be identified and quantitated utilizing this method.