GB1298172A - A method of isolating and chemically purifying amphotericin b - Google Patents

Abstract

1298172 Amphotericin B purification LENINGRADSKY NAUCHNO - ISSLEDOVATELSKY INSTITUT ANTIBIOTIKOV 8 May 1971 13906/71 Heading C2A A method of purifying crude amphotericin B comprises dissolving the crude antibiotic in dimethylformamide, adding distilled water to the solution in amount equal to half the volume of dimethylformamide used, acidifying the resulting mixture to a pH of between 2 and 3À6, removing the precipitated impurities, adding to the filtrate a volume of water equal to the volume of dimethylformamide used, adjusting the pH of the solution to a pH of from 6À5 to 7À0 and recovering the precipitated product. Preferably, the solution of the crude antibiotic in dimethylformamide is prepared by mixing 1 part by weight of crude antibiotic with from 10 to 20 parts by volume of dimethylformamide, followed by acidifying the resulting mixture with hydrochloric acid to pH 7 to 7À5. Then the mixture is stirred for 1À5 to 2 hours until the heptaenes are completely dissolved. Distilled water is then poured slowly into the mixture with stirring, in an amount of half the volume of the dimethylformamide used. The pH of the resultant solution is brought to 2À0 to 3À6 and the resultant precipitate, which consists mainly of antibiotically inactive heptaenes, is filtered off. Then further distilled water, equal in volume to that of the dimethylformamide used, is added and the pH of the mixture raised to 6À5 to 7À0 with 10% sodium hydroxide solution. The precipitated antibiotic is either filtered off or centrifuged and washed with 50% n-propyl alcohol and then acetone. Finally the amphotericin B is dried under vacuum.