Collect. Czech. Chem. Commun.
1990, 55, 1106-1111
https://doi.org/10.1135/cccc19901106
1H NMR studies of [N-MeAib1, Tyr(Me)4]ANGII and [N-MeAib1, Tyr(Me)4, Ile8]ANGII in dimethylsulfoxide by nuclear Overhauser effect (NOE) enhancement spectroscopy: cis-trans Isomerism of the His-Pro bond
John Matsoukasa, Paul Cordopatisa, Raghav Yamdagnib and Graham J. Moorec
a Department of Chemistry, University of Patras, Patras 26220, Greece
b Department of Chemistry, University of Calgary, Alberta, Canada T2N 4N1
c Department of Medical Biochemistry, University of Calgary, Alberta, Canada T2N 4N1
Abstract
The conformational properties of the Sarmesin analogues [N-MeAib1, Tyr(Me)4]ANGII and [N-MeAib1, Tyr(Me)4, Ile8]ANGII in hexadeutero-dimethysulfoxide were investigated by Nuclear Overhauser Effect (NOE) Enhancement Studies. Cis-trans isomers (ratio 1 : 6) due to restricted rotation of the His-Pro bond were observed. Interresidue interactions between the His Cα proton and the two Pro Cδ protons revealed that the major isomer was the trans.
