Action of Urea and Some of Its Derivatives on Bacteria. V. Antibacterial Activity of Methyl- and Thiourea. ∗

Conclusions

1. Methyl- and thiourea are bacteriostatic for Gram-negative bacteria. 2. The substitution of an -XHa group by-CH3 in urea results in no demonstrable increase in antibacterial activity. 3. The replacement of the = O group in urea by -Sincreases markedly the antibacterial activity. 4. Methyl urea, in the concentrations studied, does not potentiate the sulfonamides. It does have a moderate antagonistic effect on p-aminobenzoic acid.