Narcissus and Daffodil

Polarographic methods
Analysis of Amaryllidaceae alkaloids 295
Occasionally, polarographic methods have been used to determine Amaryllidaceae
alkaloids quantitatively. Volodina et al. (1970) determined the polarographic
constants of galanthamine, lycorine, pancratine, hordenine and dl-nawardine
isolated from Ungernia victoris, and used this procedure to quantify galanthamine
isolated from a chloroform extract of this species by preparative TLC. In a
subsequent study, Volodina et al. (1976) examined nine alkaloids isolated from
Ungernia polarographically. They found that, within certain limits, there was a
linear relation between the maximum current and the concentration that could be
used in analytical studies. Recently, Meng et al. (1998) reported an oscillopolarographic
titration method to determine galanthamine hydrobromide content in drug
form, using silver nitrate as the titrant, with potassium nitrate and sulphosalicylic
acid as supporting electrolytes.
Counter current chromatography (CCC)
Ma et al. (1994) described a pH-zone-refining CCC procedure for the separation
of crinine, powelline and crinamidine from Crinum moorei using a multilayer coil
planet centrifuge. Methyl tert-butyl ether containing triethylamine (5–10 mM) and
water containing HCl (5–10 mM) were used as the solvent system. The separation
was performed by using either the organic (displacement mode) or the aqueous
phase (reverse-displacement mode) as the mobile phase. Compounds were eluted
as an irregular rectangular peak and were separated into three plateaus by a UV
detector or by pH measurement of the fractions. TLC analysis of the fractions
showed a successful separation of the compounds with very narrow mixing zones.
Results observed in both displacement and reverse-displacement modes were
similar; however, the compounds were eluted in the reverse order.
Gravimetric methods
Amico et al. (1980) used a gravimetric method to quantify lycorine in various parts
of Sternbergia lutea during the different stages of its life cycle. The crude alkaloid
fraction obtained after traditional base neutral separation was crystallised from
90% ethanol to yield lycorine in crystalline form. Lycorine was separated and
its percentage based on dry weight was calculated.
Variations in the formation of pancratistatin and related isocarbostyrils in
Hymenocallis littoralis were studied by Pettit et al. (1995a) by a gravimetric method.
Pancratistatin, narciclasine, 7-deoxynarciclasine and 7-deoxy-trans-dihydronarciclasine
were isolated from H. littoralis bulbs by a series of extraction, precipitation
and separation procedures, and the variation in their content during a period of
one year was determined.
CONCLUSIONS
A number of methods have been developed during the last four decades to analyse
Amaryllidaceae alkaloids quantitatively. In recent years, reversed-phase HPLC