0000000000050037

AUTHOR

Iwona Mikołajczyk

N-[Glycyl-(Z)-α,β-dehydrophenylalanylglycyl-(Z)-α,β-dehydrophenylalanyl]glycine trifluoroacetate methanol solvate

The mol­ecular conformation of the title dehydro­peptide, H+-Gly1–ΔZPhe2–Gly3–ΔZPhe4–Gly5-OH·CF3COO−·CH3OH or C24H26N5O6+·CF3COO−·CH3OH, is characterized by the presence of two intra­molecular N—H⋯O hydrogen bonds that stabilize two type III β-turns, at the ΔZPhe2 (ΔZPhe is the Z isomer of the α,β-dehydro­phenyl­alanine residue) and Gly3, and Gly3 and ΔZPhe4 residues. As a result, the penta­peptide adopts a right-handed 310-helical conformation. All peptide units are linked trans to each other.

research product

N‐[tert‐Butoxy­carbonyl­glycyl‐(E)‐α,β‐dehydro­phenyl­alanylglycylglycyl‐(E)‐α,β‐dehydro­phenyl­alan­yl]glycine

In the mol­ecule of the title hexa­peptide, Boc0–Gly1–ΔEPhe2–Gly3–Gly4–ΔEPhe5–Gly6–OH, C31H36N6O9, there are two overlapping β-turns, one of type II on the ΔEPhe2 (ΔEPhe is isomer E of the α,β-dehydro­phenyl­alanine residue) and Gly3 residues and the second of type III′ on the Gly3 and Gly4 residues. All amino acids in the peptide are linked trans to each other. Three relatively strong intra­molecular N—H⋯O hydrogen bonds stabilize the crystal structure. Two of them, of the 4→1 type, are responsible for two β-turns in the peptide.

research product