Characterization of Polyneuridine Aldehyde Esterase, a Key Enzyme in the Biosynthesis of Sarpagine/Ajmaline Type Alkaloids

Abstract

Polyneuridine aldehyde esterase (PNA-esterase) was isolated and partially purified from cell suspension cultures of Rauwolfia serpentina BENTH. The exceptionally high substrate specific enzyme catalyses the conversion of the monoterpenoid C_10- into the C_9-unit at the stage of polyneuridine aldehyde during the biosynthesis of sarpagine/ajmaline type alkaloids. The enzymatically formed compound is the new, labile indole alkaloid 16-epivellosimine. It is this alkaloid which functions as a branch point of the biogenetic routes leading to sarpagan and ajmalan type alkaloids. PNA-esterase occupies a key position in the biosynthesis of both alkaloid groups.

Key Word Index

Rauwolfia serpentina - Apocynaceae - Cell Suspension Culture - Monoterpenoid indole alkaloids - Sarpagine/Ajmaline alkaloids - Cell-free biosynthesis - Polyneuridine aldehyde Esterase - 16-Epivellosimine