DESCRIPTIONS OF ANTIBIOTICS 



185 



positive and a few gram-negative bacteria, such 

 as members of the genera Hemophilus and Bru- 

 cella. Not active on gram-negative bacteria, yeasts, 

 or fungi. Slightly active on some saprophytic 

 mycobacteria. 



Toxieitij: LD50 (mice) 150 to 232 mg per kg in- 

 travenously. 



Reference: 1. Hata, T. et al. J. Antibiotics 

 (Japan) 8A: 9-14, 1955. 



Amice tin 



Produced by: Streptomyces vinaceus-drappus (1, 

 3, 7), S. fasciculatis (1, 3), S. sacromyceticus (6), 

 S. sindenensis (8, 11), S. plicatus (12), and a 

 Streptomyces sp. resembling *S. griseus (9). 



Synonyms: Sacromycin (9), allomycin (8), anti- 

 biotic D 13. 



Remarks: An original description of this anti- 

 biotic indicated the presence of more than one 

 antibiotic in the broth of S. vinaceus-drappus. 

 It is possible that some of these were synonymous 

 with amicetin B (plicacetin) and bamicetin (7). 



Method of extraction: I. Adsorbed from broth- 

 filtrate on a cation e.xchange resin (IRC-50, IR- 

 100, etc.) or on charcoal. Eluted from charcoal 

 with 10 per cent aqueous acid-acetone. Eluates 

 adjusted to pH 7 to 8 and freeze dried. Purified b}^ 

 countercurrent distribution (water-methylene 

 chloride or water-butanol). Anhydrous crystals 

 can also be prepared by precipitation from anhy- 

 drous methanol (7). 



II. Clarified broth extracted with butanol at 

 pH 8.5 to 9.5. Butanol extracted with dilute sul- 

 furic acid (final pH 2.0). This is repeated and 

 adjustment to pH 8.5 with seeding precipitates 

 the free base. Further purification is obtained by 

 treating a dilute HCl solution with activated 

 carbon, filtering, and reprecipitating the anti- 

 biotic from solution by adjusting to pH 8 to 8.5. 

 The slurry of hydrated needles is converted to a 

 granular, high melting point form by stirring at 

 60-65°C (3). 



Chemical and physical properties: Amphoteric 

 substance. Base: colorless. Exists in two forms: 

 needles, m.p. 165-169°C, or granular, m.p. 244- 

 245°C. Soluble in aqueous mineral acid and alkali 

 and water-saturated butanol.. Slightly soluble in 

 water at 22°C. Ultraviolet maxima at 306 m/i 

 (Ell'tn 512) in 50 per cent aqueous ethanol; 272 

 niM (Ell, 283) and 325 m^ (£^11 412) in 50 per 

 cent ethanol-50 per cent 0.1 N NaOH; 304 van 

 {E\l°m 451) in 50 per cent ethanol-50 per cent 0.1 

 N HCl; 305 m/x (ElL 465) in water; 316 m^ (^IL 

 433) in 0.1 .V HCl; and 322 m^ (^5L 470) in 0.1 

 A" NaOH. Infrared spectrum given in reference 3. 



[at* = +116.5° (c = 0.5 per cent in 0.1 A' HCl). 

 Stable in alkaline solution at >pH 8.0; stable in 

 acid. Rf values on paper chromatography given 

 in reference 3. C29H42N6O9 : C = 55.98%; H = 

 6.92%; N = 13.18%. Molecular weight about 640. 

 pKa' about 1.1, 7.0, and 10.4. Mild alkaline hy- 

 drolysis yields cytosamine. C18H32N4O6 . Acid 

 hydrolysis yields a salt of a base, cytimidine, 

 CisHitNsOj ; m.p. (of salt) 264-266°C. Structural 

 formula of amicetins (3, 4, 7, 10) given in Chapter 

 6. The dimethylamino sugar is amosamine. Hydro- 

 chloride: Fine white crystals; m.p. 190-192°C. 

 More water-soluble than amicetin. Methyl orange 

 and orange II react with amicetin to give water- 

 insoluble salts. Orange II salt: m.p. 204-206°C. 



Biological activity: Both needles and granular 

 forms have similar microI)iological activity, being 

 active largely against gram -positive bacteria, 

 especially mycobacteria (2, 4). Active in protect- 

 ing mice infected with M. tuberculosis H37R.V (1). 

 Prolong survival time of mice with transmitted 

 leukemia (Line 82), but not in mice with two other 

 leukemia strains (5). 



Toxicity: Citrate complex of amicetin: acute 

 LD50 (mice) about 90 mg per kg intravenously, 

 600 to 700 mg per kg subcutaneously. LD50 (rats) 

 about 200 mg per kg intravenously. Especially 

 toxic to guinea pigs, being 40 times as toxic as 

 streptomycin, but only ^10 as toxic as penicillin 

 given subcutaneously (2). 



References: 



1. McCormick, M. H. and Hoehn, M. M. 



Antibiotics & Chemotherapy 3: 718- 

 720, 1953. 



2. DeBoer, C. et al. J. Am. Chem. Soc. 75: 



499, 1953. 



3. Hinman, J. W. et al. J. Am. Chem. Soc. 



75: 5864-5866, 1953. 



4. Flynn, E. B.. et al. J. Am. Chem. Soc. 



75: 5867-5871, 1953. 



5. Burchenal, J. H. et al. Proc. Soc. Exptl. 



Biol. Med. «6: 891-893, 1954. 



6. Nisho, Y. et al. Japan. J. Bacteriol. 9: 



600-601, 1954. 



7. British Patent 708,686, May 5, 1954. 



8. Tatsuoka, S. et al. Ann. Rept. Takeda 



Research Lab. 13: 41-44, 1954. 



9. Himmia, Y. et al. J. Antibiotics (Japan) 



8A: 148-152, 1955. 



10. Stevens, C. L. et al . J. Am. Chem. Soc. 



78: 6212, 1956. 



11. Nakazawa, K. and Fujii, S. Ann. Rept. 



Takeda Research Lai). 16: 109-110, 1957. 



12. Haskell, T. H. et al. J. Am. Chem. Soc. 



80: 743-747, 1958. 



