Cucurbit[7]uril: A High‐Affinity Host for Encapsulation of Amino Saccharides and Supramolecular Stabilization of Their α‐Anomers in Water |
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| Authors: | Yoonjung Jang Dr. Ramalingam Natarajan Dr. Young Ho Ko Prof. Dr. Kimoon Kim |
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| Affiliation: | 1. Center for Self‐assembly and Complexity (CSC), Institute for Basic Science (IBS), Pohang, 790‐784 (Republic of Korea);2. Department of Chemistry, and Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang, 790‐784 (Republic of Korea) http://csc.ibs.re.kr/;3. Chemistry Division, CSIR‐Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700032 (India) |
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| Abstract: | Cucurbit[7]uril (CB[7]), an uncharged and water‐soluble macrocyclic host, binds protonated amino saccharides (D ‐glucosamine, D ‐galactosamine, D ‐mannosamine and 6‐amino‐6‐deoxy‐D ‐glucose) with excellent affinity (Ka=103 to 104 M ?1). The host–guest complexation was confirmed by NMR spectroscopy, isothermal titration calorimetry (ITC), and MALDI‐TOF mass spectral analyses. NMR analyses revealed that the amino saccharides, except D ‐mannosamine, are bound as α‐anomers within the CB[7] cavity. ITC analyses reveal that CB[7] has excellent affinity for binding amino saccharides in water. The maximum affinity was observed for D ‐galactosamine hydrochloride (Ka=1.6×104 M ?1). Such a strong affinity for any saccharide in water using a synthetic receptor is unprecedented, as is the supramolecular stabilization of an α‐anomer by the host. |
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| Keywords: | calorimetry host‐guest systems hydrophobic effect molecular recognition NMR spectroscopy |
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