Pfizer Handbook of Microbial Metabolites 692 



making it a new member of the depsipeptide or peptolide 

 class. This is the first report of L-a-hydroxyisovaleric acid 

 as a natural product. 



A wilt toxin, culmomarasmin, which was 200 times as 

 active as fusaric acid or lycomarasmine, has been isolated 

 from Fusarium culmorura}^^ It is a crystalline polypep- 

 tide, m.p. 215-218° (dec), stable below 0°. It is 

 ninhydrin-negative and has the analysis: C 45.31, H 7.08, 

 O 27.56, N 10.36, S 4.76, CI 4.19, C— CH3 3.17, — OCH3 

 1.08. It also contains iron (1.39% inorganic residue). 

 The amino acids are cystine, leucine, serine, aspartic 

 acid, glutamic acid, alanine, valine, affo-isoleucine, 

 proline, glycine, threonine and ammonia. 



Two dissertations on wilt toxins have been pub- 

 lished.i^^- ^^^ 



The antibacterial activities of acyclic decapeptide ana- 

 logues of gramicidin S have been measured."^ The mode 

 of action of the acyclic compounds differs from that of 

 the cycHc ones. While gramicidin S causes immediate 

 bacteriostasis, the acyclic analogues are effective only 

 after several cell divisions. The most active analogue 

 was Yio as active as gramicidin S against E. coli and Mo 

 as active against Staphylococcus aureus. 



The mushroom toxin, phalloidin, has been reported to 

 act by inhibition of oxidative phosphorylation.^^* A more 

 recent study claims that it acts, rather, by interference 

 with protein synthesis."" 



The neuromuscular blocking properties of various poly- 

 peptide antibiotics have been investigated.""" 



A yellow pigment has been isolated from E. coli.^*^ 



"*J. Kiss, Chimia 14 174 (1960). 



1^5 Hans Gempeler, tjber welkakdve Inhaltsstoffe von Endopathia 

 parasitica (Murr.) und von Fusarium martii. Dissertation, Eidgenos- 

 sische Technische Hochschule, 1959. 



136 Fritz Kugler, tjher welkdktive Inhaltsstoffe von Endopathia 

 parasitica (Murr.) und von Fusarium solani (Mart.) v. Martii, Dis- 

 sertation, Eidgenossische Technische Hochschule, 1959. 



137 B. F. Erlanger and L. Goode, Science 131 669 (1960). 

 "SBenno Hess, Biochem. Z. 328 325 (1956). 



"9 A. von der Decken, H. Low and T. Hultin, ibid. 332 503 (1960). 



i39« R. H. Adamson, F. N. Marshall and J. P. Long, Proc. Soc. 

 Exptl. Biol, and Med. 105 494 (1960). 



1*" K. Ishii and M. Sevag, Arch. Biochem. and Biophys. 77 41 

 (1958). 



