DESCRIPTIONS OF ANTIBIOTICS 



187 



\ \ c-x- 



Ha- 



c 



//. 



N— C- 



H II 

 O 



<(' 



^n, 



'O 





o / 



ff O / 



/ ^ ^^ 



c;=o 



I 



XH 



\ ^/c- C/f 



W o \ ^^Z- 



-C 



\ 



\ 



c \ 



Method of extraction: Broth-filtrate adjusted to 

 pH 1.95 and filtered. Filtrate extracted with 

 n-butanol, washed with water at pH 2.0, then 

 back-extracted into water at pH 6.4 to 7.4. Pro- 

 cedure repeated (3). I. Water-extracts from 

 butanol treated with Darco G-60 at pH 5 to 7 and 

 eluted with butanol-saturated water (pH 9). 

 Re-extracted into butanol. Extract concentrated 

 in vacuo and ether added to precipitate ampho- 

 niA'cin. Reprecipitated from anhydrous ether (5). 

 II. Water-extracts freeze dried, taken up in 

 water, adjusted to pH 2.0 with phosphoric acid, 

 and extracted into butanol. Extract filtered and 

 decolorized with activated charcoal. Butanol 

 concentrated in vacuo. Amphomycin precipitated 

 on addition of excess ethyl acetate. Can also be 

 precipitated from an aqueous solution (pH 2.2) 

 \)y isoelectric precipitation at pH 3.4. III. Puri- 

 fied by precipitation as the reineckate or as the 

 calcium salt (reaction of calcium chloride with 

 Na amphomj^cin) (1, 3). 



Chemical and physical properties: Amphoteric 

 polypeptide with an isoelectric point at 3.4 to 3.5. 

 White to off-white amorphous powder. Soluble in 

 water. Soluble in methanol as the acid form and 

 as the salt form. Soluble in higher alcohols con- 

 taining at least four carbon atoms, only in the 

 acid form. Insoluble in nonpolar solvents. End- 

 absorption (210 to 230 m^) of ultraviolet light. 

 Infrared spectrum given in reference 5. [ajc = 

 +7.5° (c = 1 per cent in water at pH 6.) Optical 

 activity decreases at higher or lower pH. Positive 



biuret test. Negative ninhydrin, Sakaguchi, Mo 

 lisch, Ehrlich-Pauly, xanthoproteic, Adamkie- 

 wicz, Ehrlich, Liebermann, and Seliwanoff tests. 

 Stable in aqueous solution for at least 1 month 

 at room temperature. Rf = 0.09 on paper chroma- 

 tography (water-saturated butanol -collidine-/3- 

 naphthalenesulfonic acid, 98:2:1). C = 54.4%; 

 H = 7.2%; N = 14.2''r (for the free acid). Mini- 

 mal molecular weight 1400 to 1500. Acid hydroly- 

 sates contain aspartic acid, glycine, valine, pro- 

 line, and a fifth unidentified amino acid (1, 3, 5). 

 Biological activity: Active on gram -positive bac- 

 teria. Not active on gram-negative bacteria, C. 

 albicans, or Trichophyton mentagrophytes (1, 3). 

 Active in vivo (mice) on 1). pneumoniae (1, 3), B. 

 anthracis, Erysipelothrix rhusiopathiae (5), Try- 

 panosoma gambiense, and T. rhodesiense infections 



(4). 



Active on d()\vn\- mildew of cucinnher, Pseudo- 

 peronospora cubensis (0). 



Toxicity: LD50 (mice) 177.8 mg per kg intra- 

 venously. LDo,, (dogs) 100 mg per kg intravenously 

 (Nasalt) (2). 



Utilization: Possible u.se in topical application 

 in gram-positive infections. 



References: 



1. Heinemann, B. et al. Antibiotics & Chemo- 



therapy 3: 1239-1242, 1953. 



2. Tisch, D. E. et al. Antibiotics Ann. 1011- 



1019, 1954-1955. 



3. British Patent 73(i,325, September 7, 1955. 



