Sj. Meunier et al., SYNTHESIS OF HYPERBRANCHED GLYCODENDRIMERS INCORPORATING ALPHA-THIOSIALOSIDES BASED ON A GALLIC ACID CORE, Canadian journal of chemistry, 75(11), 1997, pp. 1472-1482
Hyperbranched glycodendrimers containing sialic acid residues were syn
thesized in order to further understand the multivalency effect and it
s role in carbohydrate-protein interactions. Gallic acid 7 as trivalen
t core and oligoethylene glycol derivatives as hydrophilic spacers wer
e used to scaffold the dendritic backbones. alpha-Thiosialoside 16 was
conjugated onto N-chloroacetylated dendritic precursors 13, 14, and 2
6 by nucleophilic substitution to afford trivalent 17, 18, and nonaval
ent 27 sialodendrimers. Complete sugar deprotection furnished water-so
luble alpha-thiosialodendrimers 21, 22, and 29, which were used in pro
tein-binding studies. Turbidimetric analysis confirmed the strong pote
ntial of sialodendrimers 29 having nine readily accessible sialic acid
residues to bind, cross-link, and precipitate two different lectins.
Preliminary results indicated that nonavalent alpha-sialodendrimer 29
had a greater affinity towards dimeric wheat germ agglutinin (WGA) and
the lectin from the slug Limax flavus (LFA) than the corresponding tr
ivalent glycodendrimers 21 and 22.