Narcissus and Daffodil

266 M. Kreh
• High purity of the resulting product.
• No drying of the plant material in the process, since it could be shown that
drying the bulbs decreases galanthamine content.
• No use of expensive and toxic solvents during the entire procedure.
Optimum solvent for extraction
In the acidic plant sap galanthamine occurs in the form of its salts. A solvent was
required that dissolves these salts or, after alkalisation of the plant material, the
free galanthamine base. Tests were carried out using acetone, ethanol, methanol,
isopropanol, chloroform, dichloromethane, diethylether, ethylacetate, n-heptane,
n-hexane and n-pentane as the primary solvent for extraction and, following acid/
base work-up, for obtaining the raw alkaloids (before extraction with the nonwater-miscible
solvents the material was made alkaline using sodium carbonate).
The alkaloids were analysed by HPLC (see examples in Figure 9.7).
The polar, water-miscible solvents tested led to a quantitative isolation of galanthamine
even without alkalisation of the plant material. These solvents are easily
miscible with the crudely crushed plant material. The main disadvantages were
that the compounds extracted in parallel with the alkaloids caused persistent
emulsions during the following work-up, and that the procedure showed no preference
for galanthamine within the alkaloid fraction.
0 1 2 3 4 5
methanol 1
0 5 10 15 20
0 1 2 3 4 5
0 1 2 3 4 5
n-heptane 1
0 5 10 15 20
Figure 9.7 HPLC chromatograms of the alkaloid fractions obtained by using methanol
(left) and n-heptane (right) for primary extraction of bulbs; peak
1 = galanthamine.
0 1 2 3 4 5