Abstract
Monosodium salt of resorcinol, sodium p-hydroxybenzoate and salicylate were obtained by the reaction of resorcinol or the parent acids with aqueous solution of NaOH or NaHCO3, respectively. These salts were then allowed to react with excess of monochloride of di-, tri- or tetra-ethylene-glycol, which had been prepared from ethylenechlorohydrin and ethylene oxide, and NaCl precipitated was filtered and unchanged monochloride was distilled under reduced pressure from the filtrate. Repeated distillations were employed to obtain di-, tri- and tetra-oxyethylene derivatives from the residues. The compounds thus prepared were identified as expected by elementary analysis, infrared analysis and molecular weight determination.
Surface tension of their aqueous solutions was determined by Wilhelmy's meter and those of several solutions were as low as about 40 dyne/cm.
The antimicrobial activity of the derivatives was evaluated in terms of minimum inhibitory concentration by agar streak method. Tetraoxyethylene derivatives of p-hydroxybenzoic acid were observed most effective, especially for Escherichia coli, among all compounds in the present work. The activity seemed to increase with the length of oxyethylene chain in the derivatives.
