Radioimmunoassay for the quantitative determination of galanthamine.

A radioimmunoassay for the quantitation of pmol amounts of the therapeutically important Amaryllidaceae alkaloid, galanthamine, has been developed. The antiserum was raised against a conjugate of galanthamine-2-O-hemisuccinate-bovine serum albumin. The measuring range of the assay extends from 0.5 to 100 ng of galanthamine, and as little as 3.5 pmol may be detected. The antiserum is highly specific for galanthamine, showing practically no cross reactivity with different representatives of the most frequently occurring types of alkaloidal structures in Amaryllidaceae. This assay enables a rapid, sensitive and precise quantitation of galanthamine in unpurified plant extracts. The galanthamine concentration in bulbs of several Leucojum aestivum plants and the distribution of galanthamine in some Amaryllidaceae genera of South African origin have been investigated. Preliminary experiments indicate that the galanthamine-specific radioimmunoassay can be a useful tool in medicinal plant breeding as well as in tissue and cell culture studies.