GB791731A - The antiviral substance produced by the fermentation of nocardia formica - Google Patents

Abstract

<PICT:0791731/IV (b)/1> An antibiotic active against viruses and designated Noformicin is isolated from a fermentation broth in which the micro-organism Nocardia formica Nov. Spec. NRRL-2470 has been grown by contacting the broth with an adsorbent material, eluting the adsorbed material with an aqueous acidic solution, concentrating the eluate to small volume, subjecting the concentrate to chromatographic purification by adding an aqueous solution thereof to a column of adsorbent material, developing and eluting the column with aqueous acid solution and collecting fractions of eluate having a pH below 6 and concentrating the collected eluate to obtain the active material. The adsorbent may be charcoal or a cation exchange resin deriving its exchange capacity from carboxylic groups, e.g. "Amberlite" (Registered Trade Mark) IRC 50. The adsorbent used in the preliminary adsorption step and in the chromatographic purification step may be the same or different. Elution is by aqueous mineral acid, <FORM:0791731/IV (b)/1> it shows broad infra-red absorption at 3-4, 5.92; 6.0 and 6.45 microns. There are no characteristic ultra-violet peaks and very little e.g. hydrochloric or sulphuric acid, aqueous alcoholic solution of pH below 6.0 (especially where adsorbent is charcoal) and aqueous aliphatic acid containing up to six carbon atoms, e.g. acetic or propionic. A further purification is obtained by dissolving in an aliphatic alcohol such as methanol, ethanol or propanol and adding a non-solvent such as nitromethane or ether. Noformicin is obtained as the hydrochloride when hydrochloric acid is used in the elution steps. The sulphate is produced by adding triethylamine sulphate to a methanol solution of the hydrochloride. The picrate is produced by adding picric acid to an aqueous solution of the hydrochloride. Noformicin is a nitrogenous, basic water-soluble, dialysable, somewhat solvent-soluble, colourless organic substance. Active against swine influenza and plant viruses (see Group VI). Dihydrochloride contains 36.5 per cent carbon, 6.0 per cent hydrogen, 25.8 per cent nitrogen and 24.6 per cent chlorine and has the formula: absorption over the range 2300-4000 . The fermentation medium contains (a) one or more nitrogenous nutrients, e.g. meat extract, casein hydrolysate, soybean meal, corn steep solids and distillers' solubles; (b) a sugar, e.g. maltose or dextrose; and (c) minerals, e.g. sodium chloride. Preferred is a medium containing 1 to 2 per cent nitrogenous substance; 1 per cent sugar, and 0.5 per cent mineral salt. The pH is initially 7.0 to 7.2, the temperature of fermentation 20-37 DEG C. and preferably 27 DEG to 28 DEG C. and the duration of fermentation 48 to 96 and especially 72 hours.ALSO:An antiviral antibiotic noformicin, obtained by the fermentation of Nocaridia formica NRRL-2470 (see Group IV (b)), is used as a 0.1 per cent solution for the treatment of virus diseases.