A ternary metal-containing salt of polyacrylic acid with high antimicrobial activity

Starting reagents were the iron-containing polyacrylic acid Fe-PAK, a 1% aqueous solution of which is supplied for medical use under the name "Feracryl," and mercuric oxide HgO. The molecular weight of Fe-PAK was 316,000 and the iron concentration was 0.22% (by weight). The synthesis of Fe-PAK is described in [1]. Samples of Fe-PAK were dissolved in 200 ml water and HgO dissolved in 3 M NaOH was added with vigorous mixing. The mixture was allowed to react for 1 h at 25~ and the product was precipitated with a mixture of acetone-ethyl acetate (1:1). The polymer was purified from unreacted HgO and NaOH by repeated precipitations. The molar ratio of Fe-PAK to HgO varied over the range 1:0.25 to 1:2. The ternary Na-, Hg-, Fe-containing salt of polyacrylic acid consists of greenish-brown opaque flakes which are freely soluble in water. The compound started to decompose at 160~ The viscosity in 2 M NaOH at 25~ varied over the range 0.270-0.396 dl/g. The reagent ratios (Fe-PAK: HgO), and the basic properties of the polymers produced are shown in Table 1. The infrared spectra of the Na-, Hg-, Fe-containing salt of polyacrylic acid contained absorption peaks at 1400 and 1550 em "1, indicating the formation of salt bridges between the carboxyl group and the metal components. The acute toxicity was determined by intraperitoneal administration to mongrel white mice of both sexes (20-24 g), and was determined by the rapid Kerber method [3]. Doses of 3000, 600, 120, and 5 mg/kg were used. LDs0 values for 1% aqueous solutions of compounds 1, 2, and 4 were 3000, 3000, and 2004 mg/kg respectively. The polymers solutions belong to the class of virtually non-toxic substances as defined by K. K. Sidorov. The bacteriostatic activity of the Na-, Hg-, Fe-containing salt of polyacrylic acid was measured by standard methods [2]. Escherichia coli strains 5 and 6, Proteus vulgaris strains 65 and 150, and Pseudomonas aeruginosa strain 119, were used as test cultures, along with kanamycin-resistant strains of Staphylococcus. All strains were isolated from patients with purulent infections. The results are shown in Table 2.