Xanthocillin synthesis

The last step of the synthesis of the antibiotic xanthocillin by Hagedom in 1956 is the first published synthesis of an isocyanide (2) by dehydration of an A -monosubstituted formamide (1). 

For the fermentation of Penicillium notatum Westling a medium according to Czapek-Dox with some yeast extract added has been found suitable (Rothe, 1953) The cultivation is performed on rotatory shakers at 23—25 C. Synthesis of xanthocillin starts approximately 4 days after inocculation and increases as shown in Fig. 1. Obviously there is some relation between the observation of autolysis in the mycelium and the increase in the formation of xanthocillin. On approximately the 9 day the concentration of xanthocillin reaches its climax. Yields above 1 mg antibiotic per milliliter of fermentation broth are possible. 

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