HPLC coupled to a mass spectrometer (MS) was used for the analysis of galanthamine and lycorine in natural extracts of Leucojum aestivum and in their in vitro cultures grown with a precursor (ACC), inhibitors (AgNO(3), STS), or an absorber (KMnO(4)) of ethylene. The maximum galanthamine (0.002%) and lycorine (0.02%) concentrations in tissue cultures were obtained in the presence of KMnO(4). GCMS was used to investigate underivatized alkaloid mixtures from L. aestivum. Seven alkaloids were identified in in vivo bulbs. KMnO(4) led to the highest diversity of alkaloids in tissue culture extracts.