Patent GB-925481-A (GB)
Title: A new antibiotic streptozotocin
Filed: 1959-07-14
Abstract: An antibiotic, streptozotocin, active against Pasteurella multocida, S. pullorum, S. schottmuelleri, S. aureous and P. vulgaris is produced by cultivating a streptozotocin-producing variant of Streptomyces achromogenes in an aqueous nutrient medium containing an assimiliable source of carbon, nitrogen and mineral salts under aerolic and preferably submerged aerobic conditions.  The <PICT:0925481/IV(a)/1> <PICT:0925481/IV(a)/2> temperature is 24 to 37 DEG C. and the duration of cultivation 2 to 10 days.  The medium is adjusted to pH 6,5 to 7,5 initially and maintained at pH 5,5 by the continuous addition of glucose. Sources of carbon are glucose, dextrin, molasses, corn meal, starch, maltose, galactose, mannitol, soybean oil, animal and vegetable oils.  Sources of nitrogen are cotton seed meal, soybean meal, fish meal, defatted soybean meal, pepton, peanut meal, brewer's yeast, corn gluten meal and others. Sources of mineral salts are those yielding ions of sodium, potasium, calcium, phosphate and sulphate.  Streptozotocin is recovered from the clarified broth by (a) solvent extraction and (b) adsorption. Streptozotocin may be recovered from a clarified broth by adsorption on activated carbon, bentonite, diatomite or fuller's earth and elution with a solvent which is a lower fatty acid ester, lower alkanone or lower alkanol.  After removing the organic solvent from the eluate, the aqueous solution may be freeze dried.  The crude streptozotocin may be further purified by (a) counter current distribution using the solvent or solvent systems ethyl acetate and water 1 : 1; methyl ethyl ketone and water 1 : 1; or 1-butanol and 0.001N HCl 1 : 1; (b) partition chromatography using a column of diatomaceous earth and a solvent system consisting of 1-butanol, cyclohexane and water buffered at pH 4 in proportions (by volume) of 20 : 4 : 4 or methyl-ethyl ketone, cyclohexane and water buffered at pH 4 in the proportions (by volume) of 9 : 1 : 1 : 43. Streptozotocin crystallises in feather and prism forms; it contains 36.30% carbon, 5.74% hydrogen, 15.11% nitrogen and 42.85% oxygen (by difference); it is soluble in water, lower alkanones and lower alkonals (where "lower" is 1 to 6 C atoms); it is optically active, neutral and stable at pH 4; its ultraviolet spectrum is shown in Fig. 2 and its infra-red spectrum in Fig. 1.  Streptozotocin is used as a pharmaceutical and veterinary medicinal (Group VI) and as an animal and poultry feed supplements (Group VI).ALSO:Therapeutic compositions for human and veterinary use, effective against Pasturella multocida, Salmonella pullorum, Salmonella schothmuelleri, S. aureus and P. vulgaris, comprises the antibiotic streptozotocin (see Group IV (b)) and a carrier. Streptozotocin may be used as such or in the form of the acyl derivatives, e.g. the acetate or the hydrogenated derivative. The compositions are for oral, parenteral or topical use. They may be in the form of tablets, powders, granules, capsules, suspensions in edible oils with or without the addition of aluminium stearate or in water with or without the addition of a hydrophilic colloid such as sodium carboxymethyl cellulose.  They may be in the form of ointments, lotions, creams, ear drops, eye drops, aerosols, nazal sprays and suppositories.  The compositions may contain other therapeutic substances, particularly (a) sulpha drugs, e.g. sulphadiazine, sulphamerazine, sulphamethazine, sulphacetamide, sulphamethylthiadiazole and mixtures thereof; (b) antibiotics, e.g. tetracycline, oxytetracycline, chlorotetracycline, penicillins, novobiocin, neomycin, erythromycin, streptomycin, bacitracin, polymyxin, chloramphenicol, kanamycin and nystatia; (c) vitamins, e.g. thiamine, riboflavin, ascorbic acid, niacinamide, pyridoxine, pantothenic acid, pantothenate salts, Vitamin B12 and folic acid; (d) corticoids, e.g. cortisone, hydrocortisone, prednisone, prednisolone; their esters, their fuoro methyl and hydroxy analogues and their esters.  The antibiotic streptozotocin is also used as a feed supplement in promoting the growth of animals and poultry either alone or in admixture with other antibiotics.