379 Polypeptides and Related Compounds 



Rollin D. Hotchkiss, Advmices in Enzymol. 4 153 (1944). 



R. L. M. Synge, Biochem. J. 39 355 (1945). 



T. S. Work, The relation of optical form to biological 

 activity in the amino acid series, Biochem. Soc. Symposia 1 

 61 (1948). 



790 Racemomvcin B, C,;oHio>,0;,.,N..„. white, hygroscopic powder, m.p. 



150°, [2W -34° (c 6.5 in water). 



A basic antibiotic resembhng streptothricln. Acid 

 hydrolysis gives a reducing sugar and carbon dioxide, 

 ^-lysine and roseonine in the ratio 2:3:2. Racemomycin 

 B occurs in a complex with two (apparently similar) sub- 

 stances, racemomycins A and C. 



Streptomyces racemochromogemis n. sp. 



Hyozo Taniyama and Shoji Takemura, J. Pharm. Soc. Ja- 

 pan 77 1210 (1957). 



Idem., ibid. 78 742 (1958). 



791 Tyrocidine A, C66Hji60i3Ni3, colorless needles or rods, m.p. 240- 

 242° (dec), [a]v-'' -111°. A component of the tyrothri- 



cin complex. 



NH, 



CH2 



I 



I /"^ 



CH3 CH, o CH 



I O I // / \ 



CH3-CH \^NH-CH-^C^ / CH3 



CH i-Orn ^CH ^ 



X L-Val L-Leo \ /^ 



CH L-Tyr D-Phe CH"^ " 



NH C=0 



I 1 



0-=C N — -CH2 



^CH i-Glu i-Pro CH._ ^ 



CH=-^"- \ / ^"= 



OC-^ NH C^ 



\ / % 



O ^CH L-Asp ^.p,^ CH 



r/ NH_ .C^ \ 



CH. --C^CH-NH-^ \\ CH. 



OC I \ ° 



/ ° CH2 



H2N I \ J 



CH, 



