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.
Isab
Anvarhusein A
AA
Contribution from Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia. aisab@kfupm.edu.sa
Wazeer
Mohamed I M
MI
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