342 



DESCRIPTIONS OF ANTIBIOTICS 



purified from the appropriate fraction l)y treatment 

 with oleic acid-treated Darco G-60 and acetone, 

 and precipitation with absolute methanol and 

 acetone. Pleocidin II obtained by treatment of the 

 appropriate fraction with IR-45 (CI" phase), 

 lyophilization, and chromatography on cellulose 

 as above. Active fractions again lyophilized. Solid 

 taken up in methanol -3 A' HCl, treated with Darco 

 G-60, and precipitated with acetone. Pleocidin III 

 separated from contaminating traces of I and II 

 by helianthate cyclization. A fourth component, 

 pleocidin IV, is not completely purified (3). 



Chemical and physical properties: Complex hy- 

 drochloride: White hygroscopic powder. Soluble 

 in water, methanol, and ethanol. Most stable at 

 pH 4 to 6 in aqueous solution. Rf values of the 

 components of the complex given in Table 43 luider 

 "streptothricin-like antibiotics." Pleocidin I: 

 Rf = 0.50 by circular paper chromatography with 

 the system 1-propanol-pyridine-acetic acid-water 

 (15:10:3:12). Apparently identical to strepto- 

 thricin. Pleocidin II: Hydrochloride: Faintly buff- 

 colored substance, [a]" = —38° (c = 1.1562 per 

 cent in water). Infrared spectrum given in ref- 

 erence 3. Rf = 0.43 in system under I. Pleocidin 

 III: Hydrochloride: Contains traces of pleocidin 

 I. [a]'^ = _ 23.6° (c = 0.9428 per cent in water). 

 Rf = 0.35 in above system. Pleocidin IV: Rf = 

 0.26 in above system. The infrared spectra of the 

 various pleocidins do not differ ciualitatively (3). 



Biological activity: (See Table 42 and reference 

 3). Like streptothricin, pleocidin is actively trans- 

 located by tobacco, tomato, and bean plants (2). 

 Unlike streptothricin, pleocidin has anthelmintic 

 activity similar to mycothricin (3). Active on 

 Chlorella pyrenuidosa at 5 ^g per ml (4). 



Toxicity: LDso (mice) 3 mg per kg intraperi- 

 toneally, about 120 mg per kg orally (1 ). 



References : 



1. Charney, J. et al. Antibiotics & Chemo- 



therapy 2: 307-310, 1952. 



2. Gray, R. A. Suppl. Proc. Plant Physiol. 



Meetings PI. Physiol. 30: vi, 1955. 



3. Horowitz, M. I. Thesis, Rutgers University, 



1957. 



4. Tomisek, A. et al. Plant Physiol. 32: 7-10, 



1957. 



Pleoniycin 



Produced by: Streptomi/ces pleofaciens. 



Method of extraction: Filtered broth extracted 

 with }'2 volume of ethyl acetate at pH 2.0. Ethyl 

 acetate washed with }i volume of water, then 

 concentrated to I4 to '^i volume. Ethyl acetate 

 back-extracted with -^4 volume of 1 per cent Na- 



HC();i. After adjustment of the pH of the acjueous 

 extract to 2.0, extraction with ether. Ether evap- 

 orated in vacuo. Residue dissolved in ethanol. 

 Crystalline pleomycin precipitates upon cooling. 

 Chemical and physical properties: Acid, crystal- 

 lizing as glistening, colorless, rectangular plates; 

 m.p. 235°C (uncorrected). Sublimes at 200°C. 

 Solul)le in methanol, ethanol, ethyl acetate, di- 

 ethyl ether, and benzene. Alkali salts are readily 

 .soluble in water. C = 54.63%; H = 3.94%; O (by 

 difference) = 41.43%. Molecular weight, 303. 

 Empirical formula: C14H12O8. Maximal absorption 

 in ultraviolet light at 270 (E'lL 4500) and at 330 

 to 340 rrifx (Eifm 350). Maximal absorption in 

 infrared light (Nujol) at 2.90, 3.23, 3.43, 3.54, 6.29, 



6.59, 6.85, 7.08, 7.28, 7.44, 7.80, 7.88, 8.20, 8.48, 



8.60, 9.60, 10.16, 12.24, 12.62, 12.92, 13.80, and 15.07 

 ni/i. 



Biological activity: Active in vitro against vari- 

 ous gram-positive and gram-negative bacteria, in- 

 cluding Staph, aureus, B. subtilis, Pr. vulgaris, 

 Ps. aeruginosa, and M. tuberculosis H37Rv at the 

 level of 6.25 to 12.5 jug per ml. Inactive against 

 Sacch. cerevisiae and .4. niger. 



Toxicity: LDjo (mice) 35 mg jjer kg intraperi- 

 toneally. A single application of 1 mg per ml in a 

 ral)bit"s eye causes corneal opacity and edema. 



Reference: 1. Machlowitz, R. A. etal. Antibiot- 

 ics Ann. 806-808, 1954-1955. 



Pluraniycins 



Produced by: Streptomyces pluricolorescens (2). 



Method of extraction: Filtered broth at pH 7.0 

 extracted successively with ethyl acetate. Extract 

 concentrated in vacuo. Antil)iotics precipitate out 

 on addition of petroleum ether. Also adsorbed on 

 activated carbon or diatomaceous earth at pH 7.0. 

 Purified and separated by chromatographing from 

 an ethyl acetate solution on alumina, or by 

 countercurrent distribution (1 per cent ethyl 

 acetate at pH 6.55 or pH 5.3 phosphate buffer). 

 Pluramycin A is the major component, has the 

 strongest antitumor activity, and can be separated 

 from pluramycin B in the pH 5.3 system. Crystal- 

 lized from ethanol (2). 



Chemical and physical properties: Pluramycin A: 

 Basic. Orange needles (ethanol) or orange prisms 

 (ethyl acetate). Soluble in acidic water, methanol, 

 ethanol, acetone, chloroform, ethyl acetate, butyl 

 acetate, benzene, and ethyl Cellosolve. Slightly 

 soluble in ether and hexane. Insoluble in petro- 

 leum ether and water. Needles change color at 

 154°C, shrink at 157-164°C, and darken at 177°C. 

 Prisms shrink and darken at 200 -215°C. Ultraviolet 

 absorption maxima (0.01 mg ])er ml in ethanol) 



