Narcissus and Daffodil

mg/g DW
mg/g DW
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1.8
1.5
1.2
0.9
0.6
0.3
0.0
N-formylnorgalanthamine
0 2 4 6 8
Time (weeks)
Haemanthamine
0 2 4 6 8
Time (weeks)
ts
cm
ts
cm
Production of galanthamine in vitro 237
Galanthamine
As in the 250 ml flask experiment, the main alkaloid released to the medium
culture in the 500 ml flasks was found to be N-formylnorgalanthamine, especially
in the first subculturing steps. In general, there was a higher accumulation of
alkaloids in the tissue than in the liquid medium. Nonetheless, the maximum concentration
of alkaloids in this case did not take place at the end of the experiment,
probably because the plantlets still had room to grow in the bigger flasks, thus
being far from their maximum potential growth.
Comparing the effect of the size of the culture vessels on the alkaloid production
in N. confusus plantlets one can first observe that the alkaloid profile of the
explants is not always the same (Figure 7.17). Thus, in 250 ml flasks the total concentration
of alkaloids stayed more or less constant throughout the experiment,
with minor fluctuations. The main alkaloids were found to be galanthamine and
haemanthamine, showing the highest levels two weeks after starting the culture.
The accumulation of N-formylnorgalanthamine and tazettine was more or less
constant throughout the experiment, with the exception of the minimum levels
corresponding to 6 weeks of culture. The plantlets grown in 500 ml flasks exhibited
a similar behaviour, and except for tazettine, all the alkaloids reached maximum and
minimum concentrations two and six weeks after starting the culture, respectively.
mg/g DW
mg/g DW
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1.0
0.8
0.6
0.4
0.2
0.0
0 2 4 6 8
Time (weeks)
Tazettine
0 2 4 6 8
Time (weeks)
Figure 7.16 Alkaloid production by plantlets grown in 500 ml flasks. Bars represent the
SD calculated from three replicates. ts, alkaloids detected in the tissue; cm,
alkaloids released to the culture medium.
ts
cm
ts
cm