THE EFFECT OF CERTAIN BIPHENYL COMPOUNDS ON THE METABOLISM OF TWO STRAINS OF MYCOBACTERIA

¹ Department of Physiology and Pharmacology, Duke University School of Medicine, Durham, N. C.

The effects of certain biphenyl derivatives on respiration, adaptive enzyme formation, nucleic acid breakdown and ammonia accumulation has been studied in two strains of mycobacteria.

The 2- and 3-hydroxy derivatives increase respiration and ammonia accumulation in low, decrease them in high concentrations, inhibit adaptive enzyme formation and accelerate nucleic acid breakdown in both strains. Alkyl substitutions in the ring decrease most of these effects.

The 4-hydroxy derivative has a more limited action in that it increases respiration, ammonia accumulation and inhibits adaptive enzyme formation but has little effect on nucleic acid breakdown. 4,4'-Dihydroxybiphenyl, biphenyl and terphenyl are almost completely inactive and 2-aminobiphenyl causes only a small increase in respiration but a large ammonia accumulation.

Salicylate acts only on the R₁RV strain, which is closely related to the virulent tubercle bacilli. It increases respiration and ammonia accumulation but requires a higher concentration than the 2-and 3-hydroxybiphenyls. It inhibits adaptive enzyme formation. PAS also acts only on this strain, has no effect on respiration but increases ammonia accumulation. It has no effect on adaptive enzyme formation.

The possible mechanisms by which these effects are brought about are discussed.