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Abstract : |
Complexation of Ag+ with captopril, 1-[(2S)-3-mercapto-2-methylpropionyl]-L-proline, has been studied by H-1 and C-13-NMR spectroscopy. The equilibrium constants for the trans to cis isomers of captopril bound to Ag+ were measured by H-1 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 C-13 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. (c) 2005 Elsevier B.V. All rights reserved., |
