Narcissus and Daffodil

Galanthamine extraction 261
weeks by more than 400%, calculated on a fresh weight basis, peaking in April.
The galanthamine content of the bulb decreased from the middle of April until
the beginning of June, and increased again in parallel with leaf senescence. Therefore
the optimum time for harvesting and extracting bulbs would be between the
end of July and the beginning of August. Bulbs intended for galanthamine extraction
should not be lifted earlier than this.
Although there are changes in galanthamine content of the bulbs through the
growth cycle, it is not known whether some of the differences observed during the
first weeks of the study were due to the change in location of the bulbs, which were
obtained from Sint Maarten, the Netherlands (with a sandy soil) and grown at
Marburg (in a loamy soil).
Galanthamine content of the aerial parts
During this experiment, the aerial parts of the plants were investigated as well as
the bulb. Figure 9.3 shows the galanthamine content in the whole aerial parts of
Narcissus ‘Carlton’. With the growth of the leaves in spring, galanthamine content
increased dramatically until just before the start of flowering at the end of March,
and decreased slowly until the end of the flowering period. It then remained more
or less constant for some weeks, reaching the lowest level when the leaves had
completely died down.
The galanthamine content of the aerial parts was significantly lower than that of
the bulb, calculated on a fresh weight basis, but it was still in a range which would
make it useful for technical extraction. However, the removal of the leaves of
the growing crop would not be practical because of the likelihood of subsequent
rotting of the bulbs.
Location of galanthamine in the plant
Several plants of Narcissus ‘Carlton’ were separated during the flowering period
into bulb, roots, leaves, scape (stem) and flower. These parts made up the following
percentages of the whole plant: bulb, 39.8%; roots, 3.5%; leaves, 29.2%; scape,
21.9% and flower, 3.8%. After the natural opening of the capsules, the seeds of
several plants were also collected. All plant parts were tested for their content of
alkaloids and galanthamine.
Figure 9.4 shows the results of the galanthamine assay. The results demonstrated
that the bulb is clearly the most interesting part of narcissus for galanthamine
extraction, although all parts of the plant contain alkaloids and, in
particular, galanthamine. It can be calculated from the weights of the different
plant parts that bulbs planted in September (average weight, 78 g) contained an
absolute amount of galanthamine which is higher than in the whole plant during
its flowering period (average weight, 140 g). In summer, the absolute amount of
galanthamine increased again, when the new bulb units (‘daughter-bulbs’) were
growing.
Analytical HPLC allows an overview about the composition of the alkaloids in
the individual plant parts (Figure 9.5). Galanthamine is the main component only
in the bulb. In the scape, leaves and seed haemanthamine prevails, while in the
flower and root both galanthamine and haemanthamine are prominent.