Synthetic and conformational studies on dehydrovaline-containing model peptides

摘要: To explore the conformational preferences of αs-dehydrovaline (ΔVal) residue, three model dipeptide N-methylamides containing ΔVal were synthesized. Conformational investigations using 300 MHz NMR spectroscopy based on delineation intramolecularly hydrogen-bonded NH groups and Nuclear Overhauser Effect (NOE) studies. Temperature solvent dependence studies in (CD3)2SO CDC13-(CD3)2SO mixtures showed absence any intramolecular hydrogen bonding which suggests that all peptides have an extended conformation solution. Dilution CHC13 conducted IR further supported above conclusions. NOE also ruled out existence type discernible secondary structure for these peptides. behaviour dehydrovaline is contrast with corresponding ΔzPhe ΔzLeu, both stabilize s-turn (type-II) structure. These results highlight importance steric factors deciding properties dehydropeptides.