Solid and solution NMR studies of the complexation of Ag+ with the trans isomer of captopril: biological activities of this high blood pressure drug along with its Ag+ complex.
Complexation of Ag(+) with captopril, 1-[(2S)-3-mercapto-2-methylpropionyl]-L-proline, has been studied by (1)H and (13)C-NMR spectroscopy. The equilibrium constants for the trans to cis isomers of captopril bound to Ag(+) were measured by (1)H NMR spectroscopy. It is observed that the trans isomer of the drug binds more strongly to Ag(+) between pH 5 and 8, as shown by the broadening of the trans isomer's resonances in (13)C NMR spectra on complexation. A monodentate complexation of the trans captopril with Ag(+) via the thiol site is proposed based on the solid-state NMR and IR data. A superior antimicrobial activity is exhibited by the Cap-Ag(I) complex compared to captopril ligand itself against Heterotrotropic Plate Counts (HPC), Pseudomonas aeruginosa and Fecal streptococcus bacteria.
Contribution from Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia. aisab@kfupm.edu.sa
Anvarhusein A
AA
Isab
Mohamed I M
MI
Wazeer
D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology; D002216:Captopril / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006973:Hypertension / Q000628:therapy*; D007536:Isomerism; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D018030:Silver Compounds / Q000737:chemistry*; D012996:Solutions
D000890:Anti-Infective Agents; D008024:Ligands; D018030:Silver Compounds; D012996:Solutions; D002216:Captopril