A. Massoud, Y. Gohar, V. Langer
Mar 1, 2011
Citations
0
Influential Citations
26
Citations
Journal
New Journal of Chemistry
Abstract
Synthesis of bis-4,5-diazafluoren-9-one silver(I) nitrate I (dafone = 4,5-diazafluoren-9-one) and the low temperature X-ray single crystal structure of [Ag(4,5-diazafluoren-9-one)2NO3], crystal form 1, and a re-determination of [Ag(4,5-diazafluoren-9-one)2]NO3·H2O, crystal form 2 are presented. Crystal form 1 has a distorted trigonal planar coordination geometry around Ag(I) with an N–Ag–N bond angle of 123.45(7)°. Crystal form 2 has a perfect linear coordination around Ag, with N–Ag–N 180.0°. Compound I was characterized by 1H-NMR, biological activity and ESI-MS in DMSO at room temperature. The biological activity was determined against 6 different resistant clinical isolates; two Gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and four Gram-negative (Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Salmonella sp.) in comparison with 15 known antibiotics used in the treatment of diabetic foot infections. Compound I showed broad spectrum activity against all the test organisms. P. mirabilis and S. aureus and K. pneumoniae were the most sensitive clinical isolates (MIC = 4, 6 and 4 μg ml−1, respectively). Three different hydrogels containing I or Ag2SO4 were prepared and the antimicrobial activity against Ps. aeruginosa (ATCC 15442) compared, showing more or less equal activity on a weight basis, but I seems to have a significant better performance per silver ion. The Ag(I) complex also binds more effectively to calf thymus DNA than the dafone ligand itself.