RP-HPLC and NMR study of cis-trans isomerization of enalaprilat.
The angiotensin converting enzyme inhibitor, enalaprilat can exist in solution as cis and trans conformers which interconvert around the amide bond at room temperature. A HPLC with UV detection was performed to study the influence of various chromatographic operational conditions on both rotamers separation and elution of enalaprilat as a single peak. In addition nuclear overhauser enhancement difference was used for the identification of the conformers. The isomer ratio integrated from the obtained 1H NMR result were 71.5:28.5 and 76:24 at 298 and 279 K, respectively where the trans was the major form.
Bouabdallah
S
S
Laboratoire National de Contrôle des Médicaments 11bis, rue jebel Lakhdar, Bab Saadoun 1006, Tunis, Tunisia.
Trabelsi
H
H
Ben Dhia
T
T
Sabbah
S
S
Bouzouita
K
K
Khaddar
R
R
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D015773:Enalaprilat / Q000032:analysis* / Q000737:chemistry*; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods
D015773:Enalaprilat