FUNCTIONAL FLUORESCENCE LABELING OF CARBOHYDRATES AND ITS USE FOR PREPARATION OF NEOGLYCOCONJUGATES

New bifunctional reagents, 2-amino-6-carboxyethylpyridine and 2-amino- 6-cyanoethylpyridine, were designed and synthesized in order to provid e a novel procedure for preparation of neoglycoconjugates from fluores cence-labeled and purified sugar chains. Labeling of model sugar chain s with these reagents was effected by reductive amination using BH3.Me (2)NH to give corresponding 6-carboxyethylpyridylaminated (CEPA-) and 6-cyanoethylpyridylaminated (CNEPA-) derivatives, which were readily p urified by reversed phase HPLC. The reagent parts of the labeled produ cts possess the functional groups which then serve as linkers for coup ling with matrices such as proteins and polymers. A CEPA-derivative of glucose was directly coupled with the epsilon-amino group of a Lys de rivative to give a neoglycoprotein model. CNEPA-sugars were hydrogenat ed to give 6-aminopropylpyridylaminated (APPA-) derivatives, which can then be readily used for the preparation of various types of neoglyco conjugates by use of appropriate spacers as exemplified by the couplin g of APPA-maltotriose with bovine serum albumin (BSA), biotin, and acr ylic acid. The reaction of APPA-maltotriose with succinimidyl 3-(3-nit ro-2-pyridyldithio)propionate gave the corresponding amide to be used for a disulfide formation with BSA. Condensation with biotin was effec ted by use of N-hydroxysuccinimidobiotin. The conjugation of APPA-malt otriose with acrylic acid was carried out by use of 4-acryloyloxypheny ldimethylsulfonium methylsulfate to give the corresponding acrylamide, which can be used for the preparation of sugar-acrylamide copolymers.