Diastereoisomer-Selective Inclusion Complexation of Cinchona Alkaloids with a Modified β-Cyclodextrin: Fluorescent Behavior Enhanced by Chiral-Tether Binding. Short Communication
✍ Scribed by Yu Liu; Ying-Wei Yang; Heng-Yi Zhang; Bo-Wen Hu; Fei Ding; Chun-Ju Li
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 188 KB
- Volume
- 1
- Category
- Article
- ISSN
- 1612-1872
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The molecular 1 : 1 complexation of cinchona alkaloids by mono(6‐deoxy‐6‐{[(R)‐1‐(hydroxymethyl)propyl]amino})‐β‐cyclodextrin (1) in aqueous solution has been investigated by 2D‐NMR, fluorescence titration, and fluorescence‐lifetime experiments. Generally, with 1 as the host, in contrast to β‐cyclodextrin proper, strong binding of quinine (2; K~a~=84200 M^−1^) and quinidine (3; K~a~=27300 M^−1^) at pH 6.8 was observed, as monitored by an increase in fluorescence intensity, with a fair degree of diastereoisomer discrimination (ca. 3 : 1). To rationalize these results, two possible cooperative complexation modes, including specific H‐bonding interactions to the chiral tether of the cyclodextrin portion, are proposed.