A New Biosynthetic Pathway to Alkaloids in Plants: Acetogenic Isoquinolines We thank Dr. D. Marek and Dr. D. Moskau (Bruker AG, Fällanden, Switzerland), who made the cryoprobe technique available to us, Prof. L. Aké Assi (Centre National de Floristique, Abidjan Ivory Coast) for a long and fruitful collaboration on Dioncophyllaceae and Ancistrocladaceae plants, and Dr. D. Scheutzow (Universität Würzburg) for valuable advice. This work was supported by the Deutsche Forschungsgemeinschaft (SFB 251 and Graduiertenkolleg "NMR in vivo und in vitro"), by the Fonds der Chemischen Industrie, and by the Max-Buchner-Stiftung.