Pfizer Handbook of Microbial Metabolites 128 



Streptomyces alboreticuli n. sp. 



Yashiro Okami, Ryazo Utahara, Shashiro Nakamura and 

 Hamao Umezawa, J. Antibiotics (Japan) 7A 98 (1954). 



Ryozo Utahara, Yashiro Okami, Shashiro Nakamura and 

 Hamao Umezawa, ibid. 7A 120 (1954). 



243 Fradicin, C3„H3404N4, pale greenish yellow crystals, m.p. dark- 



ens without melting 180-300°, [alo'' +65° (c 1 dioxane). 



Weakly basic hexaene. U.V. maxima: 290-295. Two 

 methoxyls. 



Streptomyces fradiae 



E. Augustus Swart, Antonio H. Romano and Selman A. 

 Waksman, Proc. Soc. Exptl. Biol. Med. 73 376 (1950). 



Richard J. Hickey and Phil Harter Hidy, Science 113 361 

 (1951). 



244 Flavacid, pale yellow microcrystalline powder, m.p. 102-105° 



(dec). 



A weakly acidic hexaene. U.V. maxima: 340, 360, 

 380 mix. A tetraene with peaks at 293, 306 and 324 is 

 also present. 



A streptomycete resembling S. fiaviis 



Isao Takahashi, /. Antibiotics (Japan) 6A 117 (1953). 



L. C. Vining and W. A. Taber, Can. J. Chem. 35 1461 

 (1957). 



245 Mediocidin, yellow amorphous powder. 



A hexaene. U.V. maxima: 340, 357, 378 m/x. A 

 tetraene, probably identical with that in the flavacid com- 

 plex, is also present. U.V. maxima: 293, 306, 324. 



Streptomyces mediocidicus, n. sp. 



Ryazo Utahara, Yoshiro Okami, Shashiro Nakamura and 

 Hamao Umezawa, J. Antibiotics (Japan) 7A 120 (1954). 



L. C. Vining and W. A. Taber, Can. J. Chem. 35 1461 

 (1957). 



246 Endomycin B (Helixin B), yellow-brown powder. 



An acidic hexaene. For U.V. spectrum see first refer- 

 ence below. 



Streptomyces hygroscopicus (S. endus) 



L. C. Vining and W. A. Taber, Can. J. Chem. 35 1461 

 (1957). 



David Gottlieb, P. K. Bhattacharyya, H. E. Carter and H. W. 

 Anderson, Phytopathology 41 393 (1951). (Isolation) 



Curt Leben, G. J. Stessel and G. W. Keitt, Mycologia 44 159 

 (1952). 



R. R. Smeby, Curt Leben, G. W. Keitt and F. M. Strong, 

 Phytopathology 42 506 (1952). 



