1,3-Benzodioxole-based β- and γ-Peptide Linkages Exhibiting Unique Fluorescence, Conformation, and Self-association Properties
摘要:
Four types of beta- and gamma-peptide models were prepared from our previous asymmetric 1,3-benzodioxole and characterized by means of fluorescence and H-1 NMR spectroscopy. A beta-peptide model carrying secondary amide linkages at both of the C- and N-termini took a rigid coplanar conformation, emitting the strongest fluorescence [Ex.(max) 340 nm and Em.(max) 424 nm] among the four models. Dual intra-molecular hydrogen bonds were associated with the stable coplanar conformation. A tertiary beta-peptide model carrying a tertiary amide linkage at the C-terminus took a twisted conformation around the C-terminal to afford a pair of rotational isomers (atropisomers) detectable with H-1 NMR spectroscopy. Both secondary and tertiary gamma-peptide models showed a notable self-association property to afford dimers made of complementary intra- and intermolecular hydrogen bonds.
1,3-Benzodioxole-based β- and γ-Peptide Linkages Exhibiting Unique Fluorescence, Conformation, and Self-association Properties
摘要:
Four types of beta- and gamma-peptide models were prepared from our previous asymmetric 1,3-benzodioxole and characterized by means of fluorescence and H-1 NMR spectroscopy. A beta-peptide model carrying secondary amide linkages at both of the C- and N-termini took a rigid coplanar conformation, emitting the strongest fluorescence [Ex.(max) 340 nm and Em.(max) 424 nm] among the four models. Dual intra-molecular hydrogen bonds were associated with the stable coplanar conformation. A tertiary beta-peptide model carrying a tertiary amide linkage at the C-terminus took a twisted conformation around the C-terminal to afford a pair of rotational isomers (atropisomers) detectable with H-1 NMR spectroscopy. Both secondary and tertiary gamma-peptide models showed a notable self-association property to afford dimers made of complementary intra- and intermolecular hydrogen bonds.
Four types of beta- and gamma-peptide models were prepared from our previous asymmetric 1,3-benzodioxole and characterized by means of fluorescence and H-1 NMR spectroscopy. A beta-peptide model carrying secondary amide linkages at both of the C- and N-termini took a rigid coplanar conformation, emitting the strongest fluorescence [Ex.(max) 340 nm and Em.(max) 424 nm] among the four models. Dual intra-molecular hydrogen bonds were associated with the stable coplanar conformation. A tertiary beta-peptide model carrying a tertiary amide linkage at the C-terminus took a twisted conformation around the C-terminal to afford a pair of rotational isomers (atropisomers) detectable with H-1 NMR spectroscopy. Both secondary and tertiary gamma-peptide models showed a notable self-association property to afford dimers made of complementary intra- and intermolecular hydrogen bonds.