A new base - sophorine, with mp 59-60°C, [α]D23-18.9° (c 0.98; ethanol) - has been isolated from the epigeal part of the plant Sophora alopecuroides L. Its IR spectrum and the nature of its mass spectrometric composition have permitted sophorine to be assigned to the quinolizidine alkaloids. The13C NMR spectrum has shown the presence of 19 carbon atoms. The analysis of several of the carbon signals has confirmed the results of IR and mass spectroscopy. Additional details of the structure of sophorine have been obtained from its PMR spectrum. © 1982 Plenum Publishing Corporation.