| Abstrakt: |
Per-6-amino-2,3-dimethyl-b-cyclodextrin was prepared very effi- ciently as its hydrochloride salt from native b-cyclodextrin in four steps and 89% overall yield. O-Acetyl-protected b-D-thioglucose and b-D-thiolactose derivatives, containing short spacer arms terminated with carboxylic acid functions, were prepared by the BF 3 ·OEt 2 -catalyzed thioglycosylation of b-D-glucose pentaacetate and b-lactose octaacetate with 3-mercaptopropionic acid, respectively. Utilizing amide bond formation as the key step, these thio-b-D-glucosyl and lactosyl derivatives were coupled to per-6-amino-2,3-dimethyl-b-cyclodextrin to afford, after deprotection, perfunctionalized b-cyclodextrin-based clusters containing seven thio-b-D-glucosyl and seven b-lactosyl appendages, respectively. Molecular modeling of both these b-cyclodextrin-based clusters revealed the glucose and lactose clusters to be approximately 23 Å and 27 Å in diameter, respectively, and approximately 19 Å in height in both cases. The association constants for the complexation of the antiinflammatory drug naproxen by b-cyclodextrin, per-2,3-dimethyl-b-cyclodextrin, and the lactose cluster of b-cyclodextrin in 0.01 M phosphate buffered saline solution (pH 7.4) were found by UV-vis spectrophotometric titration to be 374 75 M 1 , 351 70 M 1 , and 165 33 M 1 , respectively. [ABSTRACT FROM AUTHOR] |
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