Tropane alkaloid metabolism by Pseudomonas AT3 cell cultures: Interchange between the nortropine and norpseudotropine catabolic pathways

• DOI: 10.1016/j.phytol.2014.04.014
• Publication Date: 2014-05-09T21:31:34Z
• Authors: Katarzyna Kosiera...; Pauline Le Faouder; Roland Molinié; Emmanuel Gentil; Jacques Lebreton; Richard J. Robins
• Keywords: Tropane; Catabolism; Metabolic pathway

Abstract Selected strains of Pseudomonas bacteria can degrade tropane alkaloids to obtain both nitrogen and carbon for growth. In order to probe the mechanisms of the catabolic enzymes involved, the metabolic process responsible for the opening of the 8-azabicyclo[3.2.1]octan-3-ol ring of nortropane alkaloids has been explored. It is found that the bacteria contain considerable flexibility in their enzyme complement and can convert (3-endo)-8-azabicyclo[3.2.1]octan-3-ol) (nortropine (2) to (3-exo)-8-azabicyclo[3.2.1]octan-3-ol) (norpseudotropine). Both of these compounds can serve as substrates for the catalytic cascade. In order to establish the proportionation between direct and indirect pathways, metabolism has been probed by competitive substrate availability and by incorporation of stable heavy labels into substrate pools. The results indicate that, while norpseudotropine is almost entirely metabolized directly, nortropine is partitioned c. 4:1 between direct and indirect catabolism.