2007 Fiscal Year Final Research Report Summary
Structure and Function of chiral Helical Foldamers Constructed by Three-Centered Hydrogen Bonding
| Project/Area Number |
18550117
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional materials chemistry
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| Research Institution | Chiba University |
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Principal Investigator |
AKAZOME Motohiro Chiba University, Faculty of Engineering, Associate Professor (10261934)
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| Project Period (FY) |
2006 – 2007
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| Keywords | Peptide Chemistry / Three-centered hydrogen bond / Supramolecular Chemistry / Foldamer |
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| Research Abstract |
We have found the 2-aminophenoxyacetic acid oligomer constructs 2-fold helical structure by three-centered hydrogen-bond. When the N-terminus of the oligomer has a nitro group, their different chromophores complicate the UV and CD spectra of their oligomers. In this context, we transformed the nitro group of oligomers into the spectroscopically-resembling methoxyactamide moiety so as to easily characterize the folding structure by the UV and CD spectra. On the UV spectra in cyclohexane, the tetramer showed hypochromic effect caused by stacking of benzene rings. Here, we characterized the chiral helical structure as new functionalized foldmers. 1. Synthesis and characterization of foldamers having different side chains: As seen in leucine zipper protein, intermolecular interactions between isobutyl groups may form bundle of alpha-helix. The spectra of foldamer having isobutyl group are similar to that of methyl group. On their H-NMR spectra, up-field shift of two terminal methyl groups of isobutyl group was observed. Since no evidence to form bundle of helical structure was found, additional molecular interaction such as hydrophobic interactions will be required to form a bundle of foldamers. 2. In the above conjunction, we found that cyclic trimers of 3-aminophenoxyactic acids construct a bowl-shaped structure, which was not affected by solvents and their side chains.
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