362 



DESCRIPTIONS OF ANTIBIOTICS 



Reference: 1. Takeiichi, T. et al. J. Aiitil)iotics 

 (Japan) 6A: 31-32, 1953. 



Sarkomycin 



Produced by: Streptunnjces erythruchruinugenes 

 (3). 



Method of extraction: Extracted from broth- 

 filtrate at pH 2.0 with butanol or ethyl acetate. 

 Back-extraction into water at pH 7.0. Adsorption 

 on charcoal at pH 2.0, and elution with 80 per 

 cent ethanol at pH 7.0 (2), or extraction from 

 water into methyl isobntyl ketone at pH 2.5 to 

 3.0. Purification by any of the following: treat- 

 ment with magnesol to remove pigment and im- 

 purities; partition chromatography on silica gel 

 (chloroform-pH 6.0 phosphate buffer); adsorption 

 from neutral aqueous solution (I) on Dowex 18X 

 (Cl~) resin and elution by gradient technique 

 with 0.1 to 1 M NaCl; adsorption from I on Amber- 

 lite IR-411 (0H-) and IR-120 (H+) mixture and 

 elution with 1.5 per cent NaCl; or countercurrent 

 distribution (ethyl acetate-pH 4.8 phosphate 

 buffer). In countercurrent distribution, 50 trans- 

 fers give a single major peak with a distribution 

 coefficient (d.c.) = +2.4 and a minor peak (d.c. 

 = 11), a decomposition product. Freed from 

 /S-sarkomj'cin by extraction of I with benzene at 

 low pH. Extract chromatographed on Florisil 

 and eluted with dioxane. /3-Sarkomycin was not 

 purified (9). 



Chemical and 'physical properties: Free acid: Oil. 

 Soluble in water, methanol, ethanol, butanol, and 

 ethyl acetate. Sparingly soluble in petroleum 

 ether. Almost insoluble in acetone, butyl acetate, 

 and ether (2, 8). Red or reddish pink color with 

 anthrone (9, 10). Negative biuret, Sakaguchi, 

 xanthoproteic, Molisch, Fehling, Benedict, Tollen, 



Scheme 1. Sarkomycin: 2-methylene-3-oxocyclo- 

 pentanecarboxylic acid. 



H 

 H3C— C- 



I 



o=c 



H 



-C— COOH 



CHo 



\c/ 

 H2 



Scheme 2. Dihydrosarkom3'cin: 2-methyl-3-oxo- 

 cyclopentanecarboxylic acid. 



Seliwanoff, Foulgen, and picric acid tests. Posi- 

 tive nitroprusside and iodine azide tests (for 

 SH groups) reported for the crude antibiotic (2) 

 were shown to be caused by ethyl acetate-soluble 

 impurities (4). Noncrystalline inactive precipi- 

 tate with 2,4-dinitrophenylhydrazine. Pure sam- 

 ples have an ultraviolet absorption spectnnii 

 maximum at 230 m^t; crude samples have only 

 end-absorption or a shoulder at 250 to 270 mix (9). 

 Infrared spectrum given in reference 9. Paper 

 chromatography (10 per cent Na citrate (pH 5.5)- 

 water-saturated CCU-isoamyl alcohol, 1:2) indi- 

 cates two components: Rf = 0.6 (major compo- 

 nent, sarkomycin) and Rf = 0.85 (/S-sarkomycin) 

 (9). Occasionally, three components (23) have 

 been observed (pH 6.5 buffer, water-saturated 

 butanol). Hydrogenation destroys antibacterial 

 activity and the anthrone reaction, but not anti- 

 tumor activity, yielding a white crystalline acid, 

 dihydrosarkomycin : CsHujOs (2-methyl-3-oxocy- 

 clopentanecarboxylic acid); m.p. 99-99. 5°C. [q;]d* 

 = +66.7° (c = 1 per cent in water) (Scheme 2). 

 Permanganate oxidation product is succinic acid. 

 Strong heating in vacuo gives a crystalline rear- 

 rangement product, CtHsOs (2-methyl-3-oxo-l- 

 cyclopentanecarboxylic acid), m.p. 175-1 76°C, 

 optically inactive and devoid of biological activ- 

 ity (vScheme 3). Sarkomycin is 2-methylene-3-oxo- 

 cyclopentanecarboxylic acid (Scheme 1) (9). Both 

 d- and 1-forms of sarkoniA^cin have been synthe- 

 sized (27, 30). Polymerizes in presence of peroxide 

 to form high molecular weight polymers (m.p. 

 280°C) which are biologically inactive (28). Stored 

 at 37°C, Na sarkomycin decomposes to form 

 sarkomycin B (Scheme 4) . Sarkomycin and sarko- 

 mj'cin B decompose (in presence of formic acid) 

 to form sarkomycin E (sarkomycin E "Z-crystal") 

 (35) (Scheme 5) (24, 33). Lyophilization of sarko- 

 mycin or sarkomycin E gives rise to an inactive 

 product, "M-cry,stal" (Scheme 6) (33). Sarko- 

 mycin reacts with HiS to give sarkomycins Si and 

 S2 (Schemes 7 and 8) (21, 22, 25) and the less well 

 described S3 factor (21, 36). 



Biological activity: Sarkomycin: Very slightly 

 active on certain gram-positive bacteria, such as 

 Staph, aureus, Streptococcus hemolyticns, Micro- 

 coccus flavus, and B. anthracis; not active on B. 

 subtilis, gram-negative bacteria, Nocardia, or 

 C. albicans (2, 8, 10, 13). Antistaphylococcal 

 activity parallels antitumor activity (2). Has 

 antitrichomonal activity (21). Bacteriostatic 

 effect lowered by cysteine, glutathione, or serum, 

 but not by methionine. Cysteine and serum have 

 no effect on the antitumor activity of the Na salt, 

 only the Ca salt. Ca salt has less antibacterial 



