GB992132A - Polysaccharides and methods for their production - Google Patents

Abstract

The invention comprises a white, solid water-soluble, heat-stable, non-dialysable acidic polysaccharide of very high molecular weight and salts thereof, which contains, in free acid form, only the elements carbon, hydrogen, oxygen and nitrogen and is characterized by the following analytical data: [a ]23D=about - 79.4 degrees in water when dried to constant weight at 50 DEG C.; in free acid form shows infra-red absorption maxima at approximately 2.95, 3.22, 3.33, 3.37, 5.73, 6.00, 6.43, 6.96, 7.24, 7.61, 8.04, 8.77, 9.49, 10.83, 11.13 and 11.52 microns in a potassium bromide disc; gives negative Molisch and anthrone tests; on hydrolysis gives a positive Elson-Morgan test; by heating with diphenylamine in acetic acid-sulphuric acid mixture gives a blue solution showing an absorption maximum at 575 millimicrons; by heating in 79% sulphuric acid gives a solution having an ultra-violet absorption maximum at 290 millimicrons; by heating in acetic acid containing 10% sulphuric acid gives a solution having absorption maxima at 283, 410 and 470 millimicrons; moves towards the anode in electrophoresis at pH values of 4 and above and is detectable as a pink spot when sprayed with para-anisidine in butanol and sulphuric acid; and has a viscosity of about 0.0151 poises at 23 DEG C. (0.3% in water). The polysaccharide is prepared by heating, with dilute acetic acid, the phenol-insoluble, water-insoluble solid residue resulting from the extraction of strains of Staphylococcus aureus with phenol and an aqueous solvent. Preferably the solid is heated with 0.1 N acetic acid for 5 minutes under pressure at 121 DEG C. The aqueous phase, containing the polysaccharide is then separated by e.g. centrifugation. The free-acid polysaccharide may be isolated by dialysis and freeze-drying and purified by means of chromatography or complex-formation. The free acid may be converted to e.g. sodium, potassium, calcium, magnesium, ammonium and amine salts by titration with appropriate bases. Aqueous solutions of the polysaccharide or salts thereof are used as vaccines for immunization against staphylococcal infections (see Division A5).ALSO:Vaccines for immunization against staphylococcal infection comprise aqueous solutions of a nitrogen-containing polysaccharide obtained by acetic acid hydrolysis of the phenol-insoluble, water-insoluble solid residue resulting after extraction of strains of staphylococcus aureus with phenol and water (Division C3). The vaccine may be rendered isotonic, e.g. by addition of sodium chloride, and may be sterilized by means of heat, ultraviolet irradiation or by addition of preservatives, e.g. thimerosal, benzethonium chloride or phenol.