Galanthamine production in ''shoot-clump'' cultures of Narcissus confusus in liquid-shake medium

Galanthamine (GAL) is increasingly used in the treatment of Alzheimer's disease. We have attempted to develop a method of producing this alkaloid using in vitro cultures of Narcissus confusus plants. The ''shoot-clump'' culture in liquid medium was shown to be an appropriate method for the micropropagation of this bulbous plant. The complete process included three steps: 1. culture of ''twin-scales'' starting from the bulbs; 2. culture of the newly formed shoots in a medium for bud proliferation (Murashige Skoog + lmg l(-1) of 2,4-dichlorophenoxyacetic acid + 5 mg l(-1) of benzyladenine), and 3. culture of ''shoot-clumps'' in a liquid-shake medium. Here we describe the effect of the addition of trans-cinnamic acid, a precursor in the biosynthesis of the Amaryllidaceae alkaloids, on the production of galanthamine and related alkaloids, and also on the growth of the ''shoot-clump'' culture. The production of galanthamine was found to be inhibited by the addition of the precursor, which promoted the production of the other alkaloid in the same biosynthetic pathway, N-formyl-norgalanthamine. The total production of galanthamine in the control cultures in day-long photoperiod was 2.50 mg per culture, of which 1.97 mg per culture were released into the medium.