Globular carbohydrate macromolecule "sugar balls" IV. Synthesis of dendritic nanocapsules with molecular recognition sites on periphery

8-Anilino-1-naphthalenesulfonic acid sodium salt (ANS)-encapsulated [O-(2-a cetamido-2-deoxy-beta-D-glucopyranosyl)-L-serine]-persubstituted poly(amido amine) (PAMAM) dendrimers (G=6.0, 7.0, and 8.0) and ANS-encapsulated [O-(b eta-D-galactopyranosyl)-L-serine]-persubstituted PAMAM dendrimers (G=7.0 an d 8.0) were synthesized by polymer reaction between PAMAM dendrimers and gl ycoNCAs (i.e., O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-beta-D- glucopyran osyl)-L-serine N-carboxyanhydride (NCA) and O-[tetra-O-acelyl-beta-D-galact opyranosyl)-L-serine NCA) in the presence of ANS in chloroform, followed by deacetylation with hydrazine monohydrate in methanol. Number of ANS molecu les per the mono(glycopeptide)-type sugar ball capsule was determined by qu antitative UV analysis of the hydrolysis product of the capsule under a bas ic condition. The results suggested that the encapsulation efficiency depen ded on the surface density of sugar residues. UV and fluorescent analyses a nd gel filtration chromatography of the capsule indicated the existence of ANS in a relatively hollow internal cavity of the mono(glycopeptide)-type s ugar ball capsule. An inhibition test of hemagglutinating activity of wheat germ agglutinin (WGA) lectin demonstrated that the capsule has a highly sp ecific molecular recognition ability owing to the sugar residues.