693 Addendum 



Acid hydrolysis yielded p-aminobenzoic acid, glutamic 

 acid, alanine, leucine and perhaps another uncharac- 

 terized substance (not a pteridine) with an U.V. maxi- 

 mum at 360 m/t. 



A total synthesis of gramicidin Jo has been achieved. ^""^ 

 The biosynthesis of this substance has been investigated.^*^ 

 The antibiotic was concentrated in the RNA-rich proto- 

 plast precipitate. 



The fact that bacitracin A (especially old samples) 

 stimulates growth of Phycomyces blakesleanus may be 

 due to conversion of the thiazoline ring of bacitracin A 

 to a thiazole ring (bacitracin F)."^ 



Papers have appeared on metabolism and actinomycin 

 production by streptomycetes'*^ and on the citric acid 

 cycle and actinomycin formation. ^^"^ 



The cytostatic activity of actinomycins is reversed by 

 high concentrations of purines and pyrimidines."" The 

 interpretation of this effect was that actinomycin may 

 react with DNA to form dye-polymer complexes. 



Mitomycin C causes bacteria to break down their DNA 

 rapidly, acid-soluble products being formed. ^■*°'' 



An actinomycin complex, aurantin, colorless crystals, 

 m.p. 255-257°, [ali,'*' - 308°, has been isolated in Rus- 

 sia.^*' The complex contains threonine, sarcosine, pro- 

 Une, valine, N-methylvaline and isoleucine. It was 

 separated into four biologically active components: A^ 

 m.p. 205°, A. m.p. 225°, A3 m.p. 226° and A4 m.p. 152°. 

 Methionine furnishes the methyl groups attached to 

 the aromatic chromophore of the actinomycins as shown 

 by labeling wdth C^*.^*^° 

 1" Y. Noda, J. Chem. Soc. Japan 80 411 (1959). 

 142 s. Otani, I. Murakami and S. Chin, Abstr. 118th Meeting, 

 Japanese Antibiotics Association. 



1*3 Sibor Ebringer, Naturwissenschaften 47 210 (1960). 

 "* Paul Prave, Arch. Mikrobiol. 32 278 (1959). 

 ^*Udem., ibid. 32 286 (1959). 



1*6 W. Kersten, H. Kersten and H. M. Rauen, Nature 187 60 

 (1960). 



i**"'" E. Reich, A. J. Shatkin and E. L. Tatum, Biochim. et Biophys. 

 Acta 45 608 (1960). 



1*' A. B. Cilaev, T. I. Orlova, B. C. Kuznetsova and I. B. Mironova, 

 Antibiotiki 3 18 (1960). 



>*■» A. J. Birch, D. W. Cameron, P. W. Holloway and R. W. Rick- 

 ards. Tetrahedron Letters No. 25 26 (1960). 



