Electronic Aspect of the Antibacterial Activity of Nitrofuran Derivatives

Abstract

Abstract In order to interpret the antibacterial activity of nitrofuran derivatives (N. F.) in connection with their electronic properties, an approximate superdelocalizability, Sr(N)′, the frontier electron density, fr(N), and the energy of the lowest vacant level, klv, were calculated. The simple Hückel MO method was adopted in this calculation. The activity for typical compounds of N. F. correlated closely with the values of klv. On the contrary, no significant correlation was found between the reactivity index, Sr(N)′, and this activity. These suggest that the bactericidal action of N. F. can be interpreted in terms not of the reactivity of N. F., but of the electron transfer from a biomolecule such as NADH to the N. F. molecule. On the other hand, between NADH and N. F. a molecular complex was found. This enables one to conclude that, by the use of their electron affinity, N. F. molecules inhibit the electron transfer coupled with the NADH of the respiratory chain in the body of bacteria.