RESUMO
A number of 5-nitrofuryl and 3-methoxy-2-nitrophenyl derivatives of 6 beta-aminopenicillanic (6 beta-APA), 7 beta-aminocephalosporanic (7 beta-ACA) and 7 beta-aminodesacetoxycephalosporanic (7 beta-ADCA) acids were synthesized by the method of mixed anhydrides or via Schiff bases. The chemical structures of the new compounds were confirmed by IR-, 1H-NMR and mass spectral data, obtained by negative ion electrospray ionization. The in vitro testing results indicated that all penicillins and cephalosporins prepared exhibited antibacterial activity equal to or in many cases considerably higher than those of ampicillin (CAS 69-53-4) and cephalexin (CAS 23325-78-2) against the Gram-positive microorganisms, excluding B. subtilis L2, B. subtilis HB2 and S. aureus 1/45 "Oxford". Their activity towards the two strains of Proteus mirabilis was also good being greater than that of cephalexin contrary to the demonstrated lower activity towards all strains of E. coli tested. The most active compounds which simultaneously possessed the broadest spectrum of antibacterial activity proved to be compounds 1 and 8 both bearing as a substituent a 5-nitrofuran group.