Inhibition of Clostridium botulinum by p-hydroxybenzoic acid n-alkyl esters.

Twelve straight-chain esters, C(5) to C(14), C(16), and C(18), of p-hydroxybenzoic acid were prepared, and their melting points, solubilities in water at 25 degrees C, infrared spectra, dissociation constants (pK(a)), and activities against Clostridium botulinum were determined. These studies also included four commercial straight-chain esters, C(1) to C(4). The most potent activity was exhibited by undecyl and dodecyl esters, which are about 300 times as active as sodium nitrite. Quadratic and cubic equations were developed correlating the activity with pK(a) values and chain length of the esters, respectively.