Über den Einbau der Tryptophan-Seitenkette und den Mechanismus der Reaktion am α-C-Atom
Open Access
- 1 September 1964
- journal article
- Published by Walter de Gruyter GmbH in Zeitschrift für Naturforschung B
- Vol. 19 (9) , 784-788
- https://doi.org/10.1515/znb-1964-0903
Abstract
Experiments with Claviceps spec., strain SD 58, showed that L-tryptophan is a more immediate precursor of ergot alkaloids than D-tryptophan. With the exception of the carboxyl group all carbon, nitrogen and hydrogen atoms of the alanine side chain are incorporated into the alkaloids from L-tryptophan. In the case of D-tryptophan the nitrogen and the α-hydrogen of the side chain are lost during incorporation. Degradative studies confirmed that the tritium of DL-tryptophan- [alanine-2 -3H] is transferred to position 5 of the ergoline ring. The results show, that n-tryptophan is converted into the L-form via the keto acid prior to incorporation. The condensation reaction at the α-carbon of the tryptophan side chain during alkaloid biosynthesis probably involves a Waldeninversion. The mechanism of this reaction is discussed.Keywords
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