| Abstract
| - A cyclomaltooligosaccharide containing seven α-(1→4)-d-glucopyranosyl units (β-cyclodextrins) wastransformed into heptakis 6-deoxy-6-iodo (13) and heptakis 6-amino-6-deoxy (25) derivatives usingknown procedures. Compound 13 was peracetylated and condensed in one pot with the knownperacetylated pseudothiouronium salts of β-d-glucopyranose (4), β-d-galactopyranose (5), or β-d-N-acetylglucopyranosylsamine (6) or with α-d-1-deoxy-1-thiomannopyranose (8) using cesiumcarbonate in dimethylformamide. Alternatively, peracetylated 4-aminophenyl-α-d-mannopyranoside(9) was transformed into either extended pseudothiouronium 11 following N-chloroacetylation andnucleophilic substitution by thiourea or into 4-isothiocyanatophenyl α-d-mannopyranoside 12 usingthiophosgene. Each of the four thiolated sugar derivatives 4−6 or 8 were also coupled to heptakischloroacetamido β-CD 26 obtained from heptakis amine 25 after N-chloroacetylation. Furtherincorporation of a hexamethylenediamine spacer arm onto heptakis iodo β-CD 13 using thiol derivedfrom mono-Boc derivative 36 and coupling to isothiocyanate 12 after suitable deprotection affordedpermannosylated derivative 38. Zemplén de-O-acetylation of all β-CD derivatives provided water-soluble persubstituted compounds containing d-glucopyranosides (18, 30), d-galactopyranosides (19,31), d-N-acetylglucosaminides (20, 32), and d-mannopyranosides (22, 24, 34, 39), respectively. Thecompounds were then evaluated for their relative binding properties toward natural carbohydratebinding plant lectins using both microtiter plate competitive inhibition experiments, double sandwichassays using horseradish peroxidase labeled lectins and by turbidimetric assays. The plant lectinsfrom Pisum sativum (pea), Arachis hypogea (peanut), Canavalia ensiformis (Concanavalin A), andTriticum vulgaris (WGA, wheat germ agglutinin) were used for β-d-glucose, β-d-galactose, α-d-mannose, and β-d-N-acetylglucosamine, respectively. All persubstituted β-CDs showed good toexcellent inhibitory properties together with abilities to cross-link their analogous plant lectins.The capacity of perglycosylated β-CDs to anchor both microtiter plate-coated lectins and theircorresponding peroxidase-labeled derivatives further confirmed the usefulness of these multivalentneoglycoconjugates in bioanalytical assays.
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