Abstract
The antibacterial activities of 64 naphthyridine derivatives were tested. Ultimately, potassium 1, 4-dihydro-1-methyl-7-[2-(5-nitro-2-furyl) vinyl]-4-oxo-1, 8 -naphthyridine-3-carboxylate (677K) was selected as the most active compound. Compound 677K exhibited excellent antibacterial activities against either gram-positive or gram-negative bacteria in vitro. Furthermore, 677K exhibited high activities against experimental infection of streptococci, diplococci, or staphylococci in mice when administered orally. The activity on diplococcal infection in mice was higher than that of aminobenzylpenicillin, tetracycline, chloramphenicol, sulfisomezole, and dihydroxymethylfuratrizine. The effect of 677K against experimental typhosis was small. Cross resistance was seen between 677K and DF, but not between 677K and NA.