Antibacterial activity and polarographic half-wave reduction potential of 2-nitrobenzo[b]furans.

Abstract

The antibacterial activities of a series of 2-nitrobenzo [b] furan derivatives against St. aureus, B. subtilis, E. coli, Sal. typhimurium, Sal. enteritidis, Sh. flexneri, Pr. vulgaris or Ps. aeruginosa were determined in vitro. Most of the compounds showed considerable activities against the bacteria except Pr. vulgaris and Ps. aeruginosa and one of them was about 30 times as active as nitrofurantoin against St. aureus. Mono- and dimethoxy derivatives (2a, 3a, 4a, 5f) were the most active. The polarographic half-wave potentials (E1/2) of the 2-nitrobenzo [b] furans at pH 7 were in a narrow range of -0.450±0.04 V, whereas the E1/2 values of regioisomeric nitrobenzo [b] furans were more negative (-0.560--0.726 V). In the case of 2-nitrobenzo [b] furans, substituent (s) on the benzene ring had little influence on the reduction potential of the 2-nitro group, whereas the antibacterial activity depended markedly on the substituent group (s).