GB850873A - Purification of monosodium novobiocin - Google Patents

Abstract

Crystalline monosodium novobiocin of enhanced purity is produced by dissolving novobiocin acid in an organic solvent mixture containing 2 to 4 parts by volume of a 1 to 4 carbon alcohol and approximately 1 part by volume of an aromatic solvent such as benzene, toluene or xylene and treating the solution with a sodium alkoxide such as methoxide to a pH of 7,0 to 7,5. The preferred solvent is 2:1 methanol-benzene which produces a product of good colour with the minimum of solvent. According to one example, novobiocin of about 88% purity is dissolved in 2:1 methanolbenzene the solution filtered and a filtered methanol solution of sodium methoxide slowly added with agitation to pH 7,1, further additions are made to pH 7,2-7,3 when monosodium novobiocin precipitates and is agitated at 25 DEG -30 DEG C. for 1 hour. Approximately 8 volumes of benzene (based on original quantity of benzene in the solvent) is then added, the mixture agitated 1 hour at 25 DEG to 30 DEG C. and filtered. After washing with benzene, the bulk of the benzene is removed without exposing the crystals to atmospheric moisture and the crystals are dried under vacuum at 50 DEG C. A substantially saturated solution of novobiocin in the organic solvent mixture is used and after the initial crystallisation step, supplemental aromatic solvent is added in amounts of 5 to 8 times the volume thereof present in the mixed organic solvent. Monosodium novobiocin is used medicinally and in the treatment of plants (see Group VI). Specification 821,819 is referred to.ALSO:Monosodium novobiocin (Group IV(b)) is administered orally in tablet or capsule form. Tablets are prepared by mixing the p powdered monosodium novobiocin with 5% solution of cellulose acetate hydrogen phthalate in methanol acetone, granulating and compressing the granules with a small amount of magnesium stearate. For the treatment of plant diseases, aqueous solutions of the salt containing various wetting or spreading agents and/or other active agents may be employed. Specification 821,819 is referred to.