Chemical Constitution and Germicidal Action.

Abstract

In two recent papers Tilley and Schaffer^1,2 have reported upon the extraordinarily constant relations between chemical constitution and germicidal activity of alcohols, phenols, resorcinols and corresponding intermediate ketones. By correcting the phenol coefficients with the ratio of the molecular weights of the test substance to the molecular weight of phenol, the computed germicidal action for certain organisms is found to vary in a constant ratio with the addition of alkyl groups.

Hence it seemed of interest to determine whether a similar constancy would appear in other chemical series. We have utilized the data reported by Kligler³ in his studies on the antiseptic properties of certain organic compounds. In a number of series, recomputation of Kligler's data on the germicidal activities of these substances for Bacterium coli A (of his series) shows the following ratios:

It is significant to note that the germicidal ratios computed from data prepared by another investigator, working with slightly different technique, give results essentially harmonious with those reported by Tilley and Schaffer. It will be observed that:

(1) In series A, the addition of a methyl group multiplies the germicidal action 2.16-2.88 times. (Tilley and Schaffer obtained ratios of circa 3.1.)

(2) In series B, the addition of a methyl group multiplies the germicidal action of aniline 2.5-2.7 times.