Antibacterial Action of N-Alkyl p -Aminobenzoic Acid Derivatives. ∗

Summary

1. The bacteriostatic and bactericidal activity of a series of N-substituted p-aminobenzoic acid derivatives have been determined.

2. Among the acids the order of decreasing activity is as follows: p-butylaminobenzoic acid > p-ethylaminobenzoic acid > p-aminobenzoic acid.

3. Of 2 procaine hydrochloride (U.S.P.) derivatives, the N-butyl derivative displays greater antibacterial action than the N-ethyl.

4. Among the methyl and ethyl esters of p-aminobenzoic acid, the N-propyl derivatives display more activity than the N-ethyl or N-butyl compounds. The latter 2 were approximately equal in respect to antibacterial action.

5. The order of decreasing activity among the p-alkylaminobenzamides was: butyl > propyl > ethyl.

6. Diethylaminoethyl-p-n-butylaminobenzate hydrochloride and p-n-butylaminobenzamide were not antagonized by the presence of p-aminobenzoic acid when tested in trypticase soy broth against Streptococcus pyogenes (C203).