Two stereospecific NADPH-dependent reductases, TR-I and TR-11, constitute a branching point in the biosynthesis of tropane alkaloids. TR-I catalyzes the stereospecific reduction of tropinone to tropine (Koelen and Gross, 1982), whereas TR-I1 reduces tropinone to pseudotropine (Drager et al., 1988). We previously characterized TRs that had been purified from cultured roots of Hyoscyamus niger (H...

The tribe Hyoscyameae (Solanaceae) is restricted to Eurasia and includes the genera Archihyoscyamus, Anisodus, Atropa, Atropanthe, Hyoscyamus, Physochlaina, Przewalskia and Scopolia. Even though the monophyly of Hyoscyameae is strongly supported, the relationships of the taxa within the tribe remain unclear. Chloroplast markers have been widely used to elucidate plant relationships at low taxon...

Hyoscyamine-6beta-hydroxylase (H6H; EC 1.14.11.11) catalyses oxidative reactions in the biosynthetic pathway leading from hyoscyamine to the more pharmaceutically valuable tropane alkaloid scopolamine. The h6h gene encoding H6H from Hyoscyamus niger was introduced, under the control of the CaMV 35S promoter, into non-hyoscyamine-producing Nicotiana tabacum and hyoscyamine-producing Hyoscyamus m...