504—Interfacial behaviour of p-aminobenzoic acid (PABA) at the mercury/solution interface: A possible role of adsorption in the bacteriostatic action of PABA antimetabolites

The interfacial behaviour of p-aminobenzoic acid (PABA) at the mercury/aqueous solution interface was examined and compared with that of its antimetabolites (sulpha drugs). On qualitative grounds the adsorption process of PABA is quite similar to that of its antimetabolites. It was shown that the common framework of the molecule, p-NH₂φ-XO₂- (XC or S), is adsorbed flat on the electrode surface and that the two groups of atoms always present in the different compounds, i.e. the p-amino group and the two oxygen atoms, are directly involved in the interaction with the charged surface.These results imply a possible role of an adsorption step in the mechanism of action of the sulpha drugs at the biological level.