N-methylornithin als vorstufe des pyrrolidinringes in tropan-alkaloiden

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“…We presently consider that ornithine is incorporated via 8-N-methylornithine (XIV) [I, 2, 31, although it must be admitted that this amino acid has not yet been detected in Datura or related species. Earlier work [58] which .apparently implicated a-Nmethylornithine rather than the 8-isomer as a precursor of tropine, was discounted when it was shown [2O] that these authors were using non-authentic a-and S-N-methylornithines in their tracer experiments. It was shown that We suggest that the utilmization of putrescine represents an "aberrant" biosynthesis.…”

Biosynthesis and Metabolism of the Tropane Alkaloids

“…We presently consider that ornithine is incorporated via 8-N-methylornithine (XIV) [I, 2, 31, although it must be admitted that this amino acid has not yet been detected in Datura or related species. Earlier work [58] which .apparently implicated a-Nmethylornithine rather than the 8-isomer as a precursor of tropine, was discounted when it was shown [2O] that these authors were using non-authentic a-and S-N-methylornithines in their tracer experiments. It was shown that The ratio of activity at these two next step is a decarboxylation to yield N-methylputrescine (XV) an established precursor of tropine [45,471.…”