100 



DESCRIPTIONS OF ANTIBIOTICS 



Reference: 1. Kaplan, M. A. et al. Antibiotics 

 & Chemotherapy 8: 491-495, 1958. 



Aiitibiotic A 6 



Produced by: Streptoniyces sp. resembling S. 

 fradiae (1). 



Method of extraction: I. Culture-l)roth treated 

 with carbon at pH 2.0 and filtered. Filtrate ad- 

 sorbed on carbon at pH 7.0. Elution with methanol 

 or 20 per cent aqueous acetone at pH 2.0. Addition 

 of acetone to eluate gives precipitate. Reprecipi- 

 tated from absolute methanol with ether, or from 

 water-methanol. Purification using an ion ex- 

 change resin (1). II. Broth-filtrate treated with 

 carbon as in I, adjusted to pH 7.2, and chroma- 

 tographed on IRC-50 (Na+ form). Eluted with 0.5 

 A^ HCl. Eluate adjusted to pH 5 to 6 and concen- 

 trated to dryness in vacuo. Precipitated from an 

 anhydrous methanol solution of residue on addi- 

 tion of ether. One component (Ab-I) purified by 

 chromatography on alumina (eluted with 50 per 

 cent methanol) and on IRC-50 (3). 



Chemical and physical properties: Basic com- 

 pound. Complex: Contains two components. End- 

 absorption of ultraviolet light. Positive Sakaguchi 

 test. Negative biuret, FeCh , maltol, Schiff, Mil- 

 Ion, xanthoproteic, nitroprusside, and Fehling 

 tests. Helianthate: m.p. 203-205°C (decomposi- 

 tion). Reineckate: d.p. 285-29C°C. 



Biological activity: Inhibits gram-positive and 

 gram-negative bacteria, including Pseudomonas 

 pyocyaneus. Active against soft rot of a variety of 

 vegetables caused by Bacillus carotovorus (2). 



Toxicity: Mice tolerate 320 mg per kg intraperi- 

 toneally (3). 



References: 



1. Tatsumi, C. and Miyaura, D. J. PVrmenta- 



tion Technol. 32: 1-7, 1954. 



2. Tatsumi, C. and Miyaura, D. J. Fermenta- 



tion Technol. 32: 3(34-366, 1954. 



3. Miyaura, J. and Tatsumi, C. J. Fermenta- 



tion Technol. 33: 533-535, 1955. 



Antibiotic A 20 



Produced by: Streptomyces sp. 



Method of extraction: Adsorbed from cultiu'e- 

 filtrate on carbon (Kerozite) at pH 8.2. Eluted 

 with acetone containing 2 per cent concentrated 

 HCl. The eluate should be al)out neutral after 

 this operation; otherwise it is difficult to separate 

 the active substance. Eluate evaporated to dry- 

 ness under reduced pressure. Residue taken up in 

 methanol, filtered to remove insoluble impurities, 

 then precipitated with acetone. Precipitated as 

 the picrate. Conversion to sulfate. 



Chemical and physical properties: Basic antil)i- 

 otic. Hydrochloride: Hygroscopic, amorphous, 

 cream-colored powder. Soluble in absolute metha- 

 nol. Slightly soluble in glacial acetic acid. Insolu- 

 ble in ethanol, isopropanol, n-butanol, acetone, 

 cliloroform, benzyl alcohol, benzene, 1,4-dioxane, 

 pyridine, and ethyl ether. Positive Sakaguchi, 

 glucosamine, Tollen, and Fehling (weak) tests. 

 Negative maltol and Molisch tests. 



Biological activity: Active on gram-positive bac- 

 teria (0.52 to 20 Mg per ml); less active on myco- 

 bacteria (15 to 60 Mg per ml), gram-negative bac- 

 teria (3.9 to > 100.0 Mg per ml), and fungi (20 to 

 100 Mg per ml). Not active on Pseudomonas . 



Toxicity: Has a retarded toxic action at low 

 doses; 50 mg per kg subcutaneously is lethal to 

 mice after 72 hours. In rats, 60 mg per kg is lethal 

 under the same conditions. 



Reference: 1. Gongalves de Lima, O. et al. Anais 

 soc. biol. Pernamliuco 13: 3-9, 1955. 



Antibiotic A 67 



Produced by: Streptomyces sp. resembling S. 

 antibioticus. 



Method of extraction: Partially extracted by n- 

 butanol. Adsorption on activated carbon and elu- 

 tion with 80 per cent methanol. 



Chemical and physical properties: Neutral sub- 

 stance. Most stal)le at pH 7.2 to 7.5. Destroyed by 

 lioiling for 1 hour at pH 7.2. Soluble in water, 

 methanol, ethanol, and acetone. Unstable in non- 

 sterile sand. 



Biological activity: Active on fungi, such as cer- 

 tain Pythium spp., Metarrhizium glutinosum, and 

 Aspergillus clavatus. Less active on other fungi, 

 such as Sclerotiniafructicola and Alternaria solani. 

 Very slightly active on certain bacteria and yeasts. 

 No activity on Rhizobium spp. 



Reference: 1. CJregory, K. F. et al. Am. J. 

 Botany 39: 405-415, 1952. 



Antibiotic A 116 



Produced by: Streptomyces sp. 



Method of extraction: Adsorbed from broth-fil- 

 trate on carbon (Kerozite) at pH 8.2. Eluted with 

 acidic methanol. Eluate concentrated to a syrup, 

 filtered to remove solids, and treated with ace- 

 tone to precipitate other impurities. Supernatant 

 evaporated to dryness. Residue taken up in metha- 

 nol and inactive residue centrifuged off. Precipi- 

 tated from methanol with acetone and li groin. 

 Operation repeated. Reprecipitated from metha- 

 nol with acetone to give Fraction C. The super- 

 natant from the precipitation of Fraction C evapo- 

 rated to dryness. Residue taken up in isopropanol 



