Complex formation of cyclo(L-Phe-L-Pro)4 with noradrenaline hydrochloride.
The 13C-NMR spectrum of cyclo(L-Phe-L-Pro)4 (1) and DL-noradrenaline hydrochloride (DL-NA.HCl) in a mixture of CDCl3 and CD3OD suggested the formation of a complex, which was demonstrated to be 1:1 from examination of the titration curves. The complex retained the C2-symmetric conformation of 1 containing two cis-peptide bonds, and was linked through hydrogen bonds between the carbonyl groups of the Phe1 and Pro2 residues, and the ammonium moiety of NA.HCl.
Ishizu
T
T
Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Hiroshima, Japan.
Hirayama
J
J
Noguchi
S
S
D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D009638:Norepinephrine / Q000737:chemistry*; D010456:Peptides, Cyclic / Q000737:chemistry*
D010456:Peptides, Cyclic; C088993:cyclo(phenylalanyl-prolyl)4; D009638:Norepinephrine