[Antibacterial activity and toxicity of a new nitrofuran]

A new nitrofuran, N-(5-nitrofurfurilidene)-5-nitrofuran-2-(N'-acetyl)carboxamidra zone designated as PAP-49 was synthesized. With the method of two-fold serial dilutions in the Hottinger's broth it was demonstrated that by its antimicrobial activity against cocci and enterobacteria PAP-49 was not inferior and in some cases it was even superior to such antibiotics and chemical drugs as benzylpenicillin, streptomycin, tetracycline, chloramphenicol, erythromycin, gentamicin, nitoxolin and furazolidone. The further study of the antibacterial properties of the new nitrofuran with the use of 101 strains of 16 bacterial species showed that its MICs for gram positive and gram negative bacteria were 0.03-3.13 and 0.78-125.0 micrograms/ml respectively. Combination of PAP-49 in the subbacteriostatic concentrations with other antimicrobial agents provided a 2-8-fold increase in the antimicrobial effect. The highest synergism was observed when nitrofuran was used in combination with aminoglycosides, benzylpenicillin or levomycetin. The primary screening revealed that PAP-49 belongs to the group of low toxic substances. Its LD50 after the oral administration to albino mice was 4631.9 mg/kg. The compound did not practically cumulate in the animal organism.