Patented June 5, 1951 2,555,761

UNITEDVSTATES PATENT OFFICE 2,555,761 ‘ RECOVERY OF STREPTOMYCIN FROM NAPHTHOL BLUE-BLACK SALT Peter‘ P. Regna, West New York, N. J ., and Isaiah >A. Solomons, III, Jackson Heights, N. Y., as ‘ signors .to Chas. P?zer & 00., Inc., Brooklyn, N. Y., a corporation of New Jersey ‘ No Drawing. Application May 14, 1947, Serial No. 748,129 4 Claims. (Cl. 260-210) 1 2 This invention relates to'the recovery of strep nitrophenylazo-Z-phenylazo-1-naphtho1-3, _ 6=di tomycin from streptomycin dye salts, and it has sulfonic acid, also known as Naphthol : Blue ,for its object to ‘providea novel and improved Black (Color ‘Index #246) , the structural formula process for this purpose. ‘of which is: Another object of the invention is to provide 5 an e?icient and economical methodof separating rnN ‘OH streptomycin of high antibiotic activity from streptomycin dye salts. Still another object is to separate streptomycin NaOsS SOaNB. salts of high antibiotic activity from streptomy 10 oin-Naphthol Blue-Black salt which may be The present invention relates to a method of precipitated directly from crude aqueous solu ‘recovering streptomycin of high antibiotic activity tions of ‘streptomycin, such as fermentation from streptomycin salts of 8-amino-7-p-nitro broths. phenylazo-2-phenylazo~l-naphthol-3, G-disulfon Various other objects and advantages will be 15 ic acid, which comprises mixing said dye‘salt apparent as the nature of the invention is ‘more with a liquid which is a solvent for streptomycin fully disclosed. hydrohalides, and reacting said mixture with a Streptomycin, anantibioticproduced by cul metal halide to precipitate a metal salt of 8 tures of Streptomyces griseus, is a highly potent arnino — 7 - p - nitrophenylazo - 2 - phenylazo-l anti-bacterial agent which is effective against a naphthol-S, S-disulfonic acid and formula solu wide variety of ‘pathogenic organisms. Clinical tion of a streptomycin hydrohalide. indications. for the‘use of streptomycin have been Our preferred method of accomplishing the observed in urinary tract infections due to gram metathesis reaction of streptomycin-Naphthol negative microorganismsyin?uenza bacillus men Blue-Black into its two components is to suspend ingitis, tracheobronchitis and pneumonia, tula the streptomycin-dye in alcohols, others of-ethlyl remia, ophthalmic infections due to-Ps.I ‘pg/acy ‘ene glycol (“cellosolves”), water or mixtures of aneus, peritonitis due to gram negative organ ‘water with acetone, alcohols and ethers of ethyl isms, and certain gram negative bacillary infec ene glycol. To the mixture is then added barium ,tions. Promising results have been obtained also chloride, so as to precipitate the barium salt of .in studies of tuberculosis. 30 Naphthol Blue-Black and leave the soluble strep It ,is known to adsorb streptomycin or its salts tomycin trihydrochloride in solution. Instead, from solutions upon activated carbon, and to however, of using barium chloride, other, alkaline elute it therefrom with solvents adjusted to a-pH earth halides, such as calcium, strontium and below neutral, but this procedure yields strepto magnesium, or other metal halides, such as zinc, mycin along with much extraneous material since cadmium, lead, etc., can be employed. The neces many‘ other substances . are simultaneously. ad sary conditions ‘are that the streptomycin ‘hy sorbed and eluted. For this reasonthis method drohaliole ‘formed in the reaction is soluble in gives a product of low potency. It is also possible the alcohol, Water, or other solvent, and that the to. prepare streptomycin concentrates by adsorp metal-Naphthol Blue-Black salt is more ‘insolu tion on zeolites or ion-exchange resins. How 40 ble than streptomycin-Naphthol Blue-Black. ever, .in removing the streptomycin from these The metathesis reaction can be carried out even adsorbents by sodium. or potassium chlorides,ithe at elevated temperatures. streptomycin becomes contaminated with consid If it is desired to recover the streptomycin' as erable amounts of these salts which are di?icult the sulfate, from a solution of the streptomycin to remove, and even“. after separation of the in hydrohalide, this can be accomplished by the organic salts gives‘concentrates with. a low strep addition of triethylamine sulfate, in which case tomycin potency. the streptomycin sulfate is removed by ?ltration, In our copending application, Serial No.‘ 743, leaving the triethylamine hydrohalide in solu 456, ?led April 23, 1947, ,now,Patent No. 2,538,847, tion. Any soluble amine sulfate may be employed we have disclosed a novel method for the re 50 in the precipitation (see our ,copending applica covery of streptomycin directly from fermenta tion, Serial No. 674,394, filed June 4, 1946, now tionbroths and partially-puri?ed solutions, by Patent No. 2,537,941). combining the streptomycin and similar basic The microbiological assays on the streptomy compounds which are present in the fermenta cin, hereinafter referred to, were carried out tion brothwith ‘the di-sodium salt oft-amino?-p 55 using Escherichia coli and Bac‘iZl-us subtilis simi» £2,555,761 4 lar to those employed for penicillin assays. The Blue-Black cake, obtained as described in Ex‘ B. subtilis plate assay is carried out by the meth~ ample 1, was suspended in 150 ml. of methanol, 0d of Schmidt and Moyer (J. Bact., v01. 47, p. 199 containing 4 g. of strontium chloride and stirred (1944)), and the E. coli turbidimetric assay by for three hours. The strontium-Naphthol Blue the procedure of Mcltfahan (J. Biol. Chem, vol. Black salt was ?ltered, and to the ?ltrate was 153, 7249 (1944)). , ' added sumcient triethylamine sulfate to precipi Other break-up procedures in which the strep tate streptomycin sulfate and strontium sulfate. tomycin-Naphthol Blue-Black salt is ?rst par The combined precipitates were suspended in tially dissolved in acetone-water mixtures, ' water and an equal amount of methanol was methanol-water mixtures, and other solvent 10 slowly added with stirring. The precipitated mixtures, such as water-propanol, water-methyl strontium sulfate was ?ltered. The ?ltrate was “cellosolve,” etc, take place, as described in the then poured into a- large volume of methanol following examples. The conditions and situa and the precipitated streptomycin sulfate was tions described herein prevail in the case of filtered and dried in vacuo over barium oxide. streptomycin-Naphthol Blue-Black salts which The dried streptomycin sulfate when assayed have been obtained from fermentation broths, against the Food and Drug Administration work from eluates of adsorbents and from solutions ing standard gave an average potency of 480 of partially-puri?ed streptomycin. meg/mg. by the B. subtilis agar plate and the E. coli turbidimetric methods.‘ Example 1 20 Example 3 Gne hundred liters of a ?ltered streptomycin fermentation broth (118 meg/ml.) was adjusted Fifty grams ‘of the wet streptomycin-Naphthol to pH 5.4 with sulfuric acid and to it was added Blue-Black cake, obtained as described in Ex 700 g. of “supercel” (a diatomaceous earth ?lter amplev 1, was suspended in 300 ml. of a 1:1 aid) and 250 g. of Naphthol Blue-Black. This acetone-water mixture, and treated with 3.5 g. large amount of ?lter aid is not necessary for ‘of barium chloride dissolved in water. The purposes of aiding the ?ltration, but is a means precipitated barium-Naphthol Blue-Black was of keeping the precipitate well dispersed in the further increased on evaporation of the acetone. subsequent conversion of the streptomycin The barium-Naphthol Blue-Black and “supercel” Naphthol Blue-Black salt. The mixture was 30 were then ?ltered and the ?ltrate was evapo stirred for one-half hour and ?ltered, and the rated, almost to dryness, in vacuo. The residue filtrate, which contained 10.0 mcg/ml. of strep was triturated with methanol, and the excess tomycin (8.5%), was discarded. The strepto barium chloride was ?ltered. The streptomycin mycin-Naphthol Blue-Black cake was partially trihydrochloride ?ltrate was diluted with water, dried on a Buechner funnel, and was then the methanol was distilled in vacuo, and the divided into a number of portions from which aqueous solution was frozen, dried under high the streptomycin was recovered, as described im vacuum and further dried in vacuo over barium mediately below as well as in Examples 2 to 4 oxide. The dried streptomycin trihydrochloride inclusive. 7 when assayed against the Food and Drug Ad A portion (5%) of the wet streptomycin 40 ministration working standard gave an average Naphthol Blue-Black cake was suspended in 500 potency of 480 meg/mg. by the B. subtilis agar ml. of methanol, containing 4 g. of barium plate and the E. coli turbidimetric methods. chloride and stirred for two hours. The pre cipitated barium salt of the dye was ?ltered and Example 4 washed with methanol, and the ?ltrate con Fifty grams of the wet streptomycin-Naphthol tained 500,000 mcg. (85% step yield) of strep Blue-Black cake, obtained as described in Ex‘ tomycin trihydrochloride. Triethylamine sul ample 1, was dissolved in 200 ml. of 3:2 methyl fate was added to the ?ltrate until precipitation “cellosolve”-water mixture and treated with an was complete. The combined precipitates were aqueous solution containing 3.5 g. of calcium ?ltered and suspended in water to remove the chloride. The precipitated calcium-Naphthol streptomycin sulfate from the barium sulfate. Blue-Black and the “supercel” was removed by The latter was ?ltered, and the aqueous solution, ?ltration and the ?ltrate was found to contain containing the streptomycin sulfate, was frozen, 90% of the streptomycin. The solution was then dried under high vacuum and further dried in diluted with fresh methyl “cellosolve” and then vacuo over barium oxide. The dried material treated with an excess of triethylamine sulfate. when assayed against the Food and Drug Ad The combined precipitates of streptomycin and ministration working standard gave an average calcium sulfates were removed by ?ltration, sus potency of 485 meg/mg. by the B. subtilis agar ' ' pended in water and treated with an equal volume plate and the E. coli turbidimetric methods. of methanol with stirring. The precipitated cal In place of barium chloride, equivalent cium sulfate was ?ltered. The ?ltrate ‘was then amounts of calcium chloride or strontium chlo poured into a large volume of methanol, and the ride can be used. In addition, the corresponding precipitated streptomycin sulfate was ?ltered and alkaline-earth bromides may be employed yield dried in vacuo over barium oxide. The dried ing streptomycin trihydrobromide and the in streptomycin sulfate when assayed against the soluble akaline-earth salts of Naphthol Blue Food and Drug Administration working standard Black. Furthermore, heavy metal halides, such gave an average potency of 520 meg/mg. by the as aluminum chloride, ferric chloride, zinc B. subtilz‘s agar plate and the E. coli turbidie bromide, manganese chloride, copper chloride, metric methods. etc., are also suitable for this purpose. The con Erample 5 version can be carried out, also, at elevated tem perature, thereby greatly shortening the reaction To 5 liters of a ?ltered streptomycin fermenta time. . tion broth, 120 meg/ml. at pH 6.8, was added 50 Example 2 g. of Norite A (a carbon adsorbent). The mix ture was stirred for 1 hour and ?ltered over a Fifty grams of the wet streptomycinNaphthol ' “supercel” pre-coated ?lter. The carbon-ad; 2,655,761 6 sorbate was suspended in 300 ml. of 0.1 N hydro the B. subtilz's agar plate and the E. coli turbi chloric acid and stirred for one-half hour. The dimetric methods. mixture was then ?ltered, and the clear ?ltrate The invention claimed is: was neutralized with sodium hydroxide to pH 5.5 1. A process Which comprises suspending a and re-?ltered. Several of the above adsorption 5 streptomycin salt of Naphthol Blue-Black in a experiments were combined until 2500 ml. were solvent which is capable of dissolving strepto accumulated containing 1.5 g. of streptomycin. mycin hydrochloride, adding a solution of barium To the solution at pH 5.5 was added 30 g. of chloride in said solvent in excess of the amount “supercel” and 12 g. of Naphthol Blue-Black, dis~ required to precipitate all of the Naphthol Blue solved in water. After stirring one hour, the 10 Black as an insoluble barium salt of Naphthol whole precipitate was ?ltered. The ?ltrate con Blue-Black and form a solution of streptomycin tained 25 meg/m1. (5%). The precipitate was hydrochloride, removing the excess of said barium suction dried on a Buechner funnel and sus chloride remaining in the solution of the strepto pended in 500 ml. of methanol (suf?cient to make mycin hydrochloride and isolating the strepto the ?nal solution at least 90% with respect to 15 mycin as a metal-free, Water-soluble salt of high methanol), containing 1 g. of calcium chloride. antibiotic potency. The suspension was stirred for several hours in 2. The process of claim 1, in which the solvent order to convert the Naphthol Blue-Black to the is aqueous methanol. calcium salt and the streptomycin to the trihy 3. The process of claim 1, in which the solvent drochloride. The calcium-dye salt was ?ltered 20 is aqueous acetone. and the ?ltrate found to contain 1.27 g. (85%). 4. The process of claim 1, in which the excess To the ?ltrate was added su?icient triethylamine of barium chloride is converted to barium sulfate. sulfate to precipitate streptomycin sulfate and PETER P. REGNA. calcium sulfate. On ?ltering the precipitates, ISAIAH A. SOLOMONS, III. the ?ltrate was found to contain 2% of strepto 25 mycin. The combined precipitates were suspend REFERENCES CITED ed in 65 ml. of water, and an equal volume of The following references are of record in the methanol was slowly added with stirring; the ?le of this patent: ‘ completely-precipitated calcium sulfate was ?l tered. The ?ltrate, containing the streptomycin 30 UNITED STATES PATENTS solution, was diluted with water, the methanol Number Name Date Was evaporated in vacuo, and the aqueous solu 2,022,678 Kritchevsky et al. ____ Dec. 3, 1935 tion was frozen, dried under high vacuum and 2,446,102 Peck ______July 27, 1948 further dried in vacuo over barium oxide. The 2,462,175 Folkers ______Feb. 22, 1949 dried streptomycin sulfate when assayed against the Food and Drug Administration working stand OTHER, REFERENCES ard gave an average potency of 580 mcg./mg. by Peck et al., J. A. C. 3., vol. 67 (1945), pp. 1866 1867.