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A Model Mechanism for the Enzymatic Synthesis of Lupin Alkaloids

1979; De Gruyter; Volume: 34; Issue: 9-10 Linguagem: Inglês

10.1515/znc-1979-9-1009

1865-7125

Michaël Wink, Thomas Hartmann, Hans-M artin Schiebel,

Chemical synthesis and alkaloids

Abstract A crude enzyme preparation obtained from cell suspension cultures of Lupinus polyphyllus catalyzes the pyruvate dependent conversion of cadaverine into the tetracyclic lupin alkaloids. As the first reaction product 17-oxosparteine could be identified by gas-liquid chromatography and mass spectroscopy. In some experiments sparteine was found additionally. A participation of di­amine oxidase could be ruled out. The cadaverine-pyruvate transaminating enzyme system (17-oxosparteine synthase) catalyzes the formation of 17-oxosparteine from three cadaverine units without releasing free intermediates. These results are inconsistent with the hypothetical mechanism thus far formulated for the lupin alkaloid biosynthesis. A new enzymatic model mechanism is proposed regarding both the results of the enzymatic experiments and those of the in vivo tracer studies.