Effect of Benzophenone and Allied Compounds on Human Tubercle Bacilli in vitro

Summary and Discussion

Various derivatives of benzophenone inhibited the growth of tubercle bacilli. 2, 4′-Dichlorobenzophe-none was bacteriostatic in high dilution, ortho and para chlorobenzophenone to a lesser degree. These compounds were effective in spite of their relative insolubility in the aqueous media. Attempts are being made to increase the solubility of these compounds without decreasing their bacteriostatic effect. Other halogen derivatives are also being investigated. The para methyl and methoxy derivatives also inhibit growth. It is possible that other higher alkyl derivatives may show an increased effect. All of the di-para derivatives (amino, methyl, methoxy, chloro) were inferior to the mono para compounds. Substitution of the hydrogen atoms of the amino groups with alkyl groups did not increase the effect. Benzil, benzanilide, and o-benzoyl benzoic acid did not inhibit in the lowest dilution. The sulfoxide and sulfone derivatives, including promin, were low in bacteriostatic action, although no analogous halogen or alkyl derivatives of these compounds were tested. 2, 4′-Dichlorobenzo-phenone also inhibited a virulent strain of tubercle bacilli in high dilution in liquid media, but not on solid media.