Pfizer Handbook of Microbial Metabolites 394 



831 Thiostrepton, colorless crystals, m.p. 246-256° (dec), [ajo"^ 



—98.5° (c 1 in glacial acetic acid). 



A weakly basic polypetide. Probable amino acid con- 

 tent: leucine (or isoleucine), valine, alanine, threonine, 

 proline, lysine, glycine, aspartic acid, glutamic acid, 

 cystine and tryptophan. 



Streptomyces sp. 



John Vandeputte and James D. Dutcher, "Antibiotics An- 

 nual 1955-1956," Medical Encyclopedia, Inc., New York, p. 

 560. 



832 Antibiotic 899, reddish yellow amorphous powder, m.p. 115- 



120°. 



A neutral compound with spectra similar to those of 

 streptogramin. 



Streptomyces sp. resembling S. virginiae 

 P. De Somer and P. Van Dijck, Antibiotics and Chemother- 

 apy 5 632 (1955). 



833 Amphomycin, colorless crystals, [ajn"' +7.5° ±5 (c 1 in water 



at pH 6). 



An acidic (amphoteric) polypeptide, minimal molecu- 

 lar weight about 1500. 



Streptomyces canus 



Bernard Helnemann, Murray A. Kaplan, Robert D. Muir 

 and Irving R. Hooper, Antibiotics and Chemotherapy 3 1239 

 (1953). 



834 Aspartocin. 



An acidic polypeptide similar to amphomycin. C 53.2, 

 H 7.6, N 13.2, S 0.42, no halogen. Hydrolyzes to 4 

 moles of L-aspartic acid, 2 moles of glycine, 1 mole of 

 L-proline, 1 mole of L-valine, a,y8-diaminobutyric acid, 

 a-lL],/8-methylaspartic acid, D-a-pipecoHc acid and an un- 

 saturated fatty acid. 



Streptomyces griseus var. spiralis, S. violaceus 



Yields of 1 to 10 g. per liter were obtained. 



A. J. Shay, J. Adam, J. H. Martin, W. K. Hausmann, P. Shu 

 and N. Bohonos, 7th Annual Symposium on Antibiotics, Wash- 

 ington, D. C, 1959. 



J. H. Martin and W. K. Hausmann. J. Am. Chem. Soc. 82 

 2079 (1960). 



835 Zaomycin, m.p. 242-246° (dec). 



A polypeptide resembling amphomycin. 

 Streptomyces zaomyceticus n. sp. 



