Pfizer Handbook of Microbial Metabolites 338 



pipecolic acid can be incorporated.'" It should be noted that 

 certain amino acid analogues can be incorporated into enzymes 

 and other proteins without impairing their normal functions." 



Professor Hans Brockmann and his collaborators at Gottingen, 

 who were primarily responsible for determining the structure of 

 the first well-characterized actinomycin, actinomycin C^,'- have 

 succeeded in synthesizing this substance' ' and it should be pos- 

 sible now to prepare an even wider variety of actinomycins. 



Valinomycin, shown opposite, can be hydrolyzed to its con- 

 stituents: L-valine, D-valine, D-a-hydroxyisovaleric acid and 

 L-lactic acid. It has been found'* that L-valine- l-C* in the 

 medium was incorporated to an equal extent into the D-valyl 

 and L-valyl portions of the molecule, to a lesser extent into the 

 D-a-hydroxyisovaleric acid, and not at all into the lactic acid. 

 D-Valine-l-C* was incorporated only to a slight extent. Similar 

 results have been obtained in studies on the origin of the 

 D-valine moieties in penicillin and in actinomycin. 



The co-occurrence of valine with the biosynthetically related 

 -z-hydroxyisovaleric acid in several polypeptides is noteworthy. 

 Also conjugated with certain polypeptides are 6-methyloctanoic 



CHs— CH2— CH— CH2— CH.— CH,— CH,— COOH 



I 

 CH3 



6-Methyloctanoic Acid 



CH3— CH2— CH,— CHo— CH.— CH.— CH>— CH— CHo— COOH 



I 

 OH 



3-Oxydecanoic Acid 



acid and 3-oxydecanoic acid. The latter substance has been 

 found conjugated with bacterial carbohydrates too. 



10 Edward Katz and WilHam Goss, Nature 182 1668 (1958); S. A. 

 Waksman, E. Katz, W. A. Goss, L. H. Pugh, M. Solvtorowsky, and 

 N. A. Auerbach, Science 129 1290 (1959); E. Katz and W. A. Goss, 

 Biochem. J. 73 458 (1959); A. W. Johnson and A. B. Mauger, ibid. 

 73 535 (1959); WiUiam A. Goss and Edward Katz, Antibiotics and 

 Chemotherapy 10 221 (1960). 



" E.g., Akira Yoshida and Mekoto Yamasaki, Biochim. et Biophys. 

 Acta 34 158 (1959). 



1- H. Brockmann, G. Bohnsack, B. Franck, H. Grone, H. Muxfeldt 

 and C. Siiling, Angeiv. Chem. 68 70 (1956); H. Brockmann, N. 

 Grubhofer, H. Kalbe and W. Kass, Chem. Ber. 84 260 (1951); H. 

 Brockmann, Angeiv. Chem. 66 1 (1954); H. Brockmann and B. 

 Franck, ibid. 68 70 (1956) and other papers in this series. 



1-^ H. Brockmann, W. Sunderkotter, K. W. Ohly and P. Boldt, 

 NatUTivissenschaften 47 230 (I960); H. Brockmann and H. Lackner, 

 ibid. 47 320 (1960). 



"J. C. MacDonald, Can. J. Microbiol. 6 27 (1960). 



