Pfizer Handbook of Microbial Metabolites 1 24 



227 PA-166, C35H53O14N (proposed), colorless powder, m.p. gradual 



dec. up to 260°, [a]n'' +275° (c 0.2 in pyridine). 



An amphoteric tetraene. U.V. maxima: 291, 304, 319 

 in aqueous methanol. Positive ninhydrin, 2,4-DNPH and 

 Fehling's tests. Three C-methyl groups. 



Streptomyces n. sp. 



B. K. Koe, F. W. Tanner, Jr., K. V. Rao, B. A. Sobin and 

 W. D. Celmer, "Antibiotics Annual 1957-1958," Medical En- 

 cyclopedia, Inc., New York, p. 897. 



228 Etruscomycin, CagH^TOi^N, white crystals, [a]D^° +296° (c 1 in 



pyridine ) . 



A tetraene antibiotic. I.R. peaks at: 2.91, 3.38, 5.83, 

 6.30, 9.44, 9.55, 11.85;x. U.V. peaks at: 290, 300, 316 m^x. 



Streptomyces lucensis n. sp. 



F. Arcamone, C. Bertazzoli, G. Canevazzi, A. DiMarco, M. 

 Ghione and A. Grein, Giorn. Microbiol. 4 119 (1957). 



229 Lagosin (Antibiotic A-246), C41H66-70O14. m.p. ^235° (dec), 



[a]ir" -160° (c 0.2 in methanol). 



An antifungal pentaene macrolide antibiotic with the 

 following partial structure : * 



n— CsHnCHOH 



I 



O— CO— CH— c— c— c— c— c— c— c— c— c— c— 



I 



CH3— CH— CH— (CH=CH)4— CH=C CH C— 



> C6H30-34O9 



OH CH3 OH OH 



Streptomyces sp. 



M. L. Dhar, V. Thaller and M. C. Whiting, Proc. Chem. Soc, 

 148 (1958)._ 



M. L. Dhar, V. Thaller, M. C. Whiting, Ragnar Ryhage, 

 Stina Stalberg-Stenhagen and Einar Stenhagen, ibid., 154 

 (1959). (Structure) 



S. Ball, Christine J. Bessell and Aileen Mortimer, J. Gen. 

 Microbiol. 17 96 (1957). (Isolation) 



230 Nystatin (Fungicidin, Mycostatin) C46H77O19N (tentative), yel- 

 low powder, m.p. dec. above 160°, but no definite m.p., 

 [aln'^ +10° (in glacial acetic acid). 



An amphoteric tetraene. U.V. maxima at: 280, 291, 

 304, 318 m/A. Contains a mycosamine moiety: 



NH2 

 HO I OH 



O: 



HO CH3 



* See addendum. 



