1990 Fiscal Year Final Research Report Summary
Chiral Recognition by Noncyclic and Cyclic Oligosaccharides
| Project/Area Number |
01550657
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
有機工業化学
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| Research Institution | Doshisha University |
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Principal Investigator |
HASHIMOTO Shizunobu Doshisha University, Faculty of Engineering, Professor, 工学部, 教授 (90066027)
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| Co-Investigator(Kenkyū-buntansha) |
KANO Koji Doshisha University, Faculty of Engineering, Professor, 工学部, 教授 (60038031)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Cyclodextrins / Noncyclic Oligosaccharides / Chiral Recognition / Bilirubin / Pamoic Acid / Binaphthols / Circular Dichroism / NMR |
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| Research Abstract |
Saccharides are the most abundant and natural hydrocarbons having lots of chiral centers. In this works, we carried out the basic studies on chiral recognition by cyclic and noncyclic oligosaccharides and obtained the following results :
(1) Bilirubin (BR) forms chiral complexes with cyclodextrins (CDx) and noncyclic oligosaccharides through hydrogen-bonding interaction. In complexation, the secondary hydroxyl groups of CDx play an important role for hydrogen bonding.
(2) (S)-1, 1'-Bi-2-naphthol is selectively included in the trimethyl-beta-CDx cavity. The ability of trimethyl-beta-CDx to recognize the chirality is higher than that of beta-CDx itself. This suggests that the asymmetric nature of beta-CDx cavity is amplified by methylation.
(3) Nucleosides forms chiral BR complexes. The circular dichroism study using various nucleosides suggests the binding sites. For example, the nitrogen at N-7 position and the 2'- and/or 3'-hydroxyl groups of adenosine participate in the hydrogen bond formation between the nucleoside and BR.
(4) (R)-Helix pamoic acid is a preferential guest for gamma-CDx. The enormously large binding constant of the pamoic acid-gamma-CDx complex may be ascribed to the hydrogen bond between a carboxylate anion of the guest and the secondary hydroxyl group of the host. The NMR study suggests the structure of the complex.
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