Narcissus and Daffodil

236 C. Codina
mg/g DW
mg/g DW
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
N-formylnorgalanthamine
0 2 4 6 8
Time (weeks)
Haemanthamine
0 2 4 6 8
Time (weeks)
ts
cm
ts
cm
Galanthamine
In general, the accumulation of alkaloids was always higher in the tissue than in
the culture medium, except in the case of the galanthamine type alkaloids,
especially four weeks after starting the experiment in the liquid medium culture.
From the beginning, N-formylnorgalanthamine was the alkaloid most susceptible
to being released into the culture medium. In all the cases, the maximum concentration
of alkaloids in tissue occurred in the final step of the experiment. This was
probably due to the fact that the plantlets kept in this kind of flask were close to
the limit of exponential growth, when the accumulation of secondary plant metabolites
is usually at its highest (Maldonado-Mendoza et al., 1993).
500 ml flasks experiment
As in the former experiment, plantlets cultivated in 500 ml flasks produced
galanthamine and haemanthamine as the major alkaloids, also showing maximum
concentration two weeks after starting the experiment, with total (tissue and
culture medium) values of 1.24 and 1.32 mg/g DW, respectively (Figure 7.16). In
addition, N-formylnorgalanthamine and tazettine also reached maximum levels in
the same period, 1.18 and 0.38 mg/g DW, respectively.
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 7.15 Alkaloid production by plantlets grown in 250 ml flasks. Bars represent
the SD calculated from three replicates. ts, alkaloids detected in the tissue;
cm, alkaloids released to the culture medium.
mg/g DW
mg/g DW
ts
cm
ts
cm