<jats:p>From <jats:italic>S. nemorensis</jats:italic> L., var. <jats:italic>subdecurrens</jats:italic> GRISEB. there were isolated the previously obtained alkaloids nemorensine (<jats:italic>I</jats:italic>), retroisosenine (<jats:italic>II</jats:italic>), bulgarsenine (<jats:italic>III</jats:italic>) and, in addition, the alkaloid oxynemorensine which was assigned the structure <jats:italic>VIII</jats:italic> on the basis of the interpretation of the <jats:sup>1</jats:sup>H-NMR, <jats:sup>13</jats:sup>C-NMR, mass spectra, and on that of the identification of the products of hydrolysis and reduction. Furthermore, the isolation of the <jats:italic>cis</jats:italic>-nemorensic acid (V) as well as that of the unsaturated acid <jats:italic>IV</jats:italic>, and the transformation of bulgarsenine (<jats:italic>III</jats:italic>) to nemorensine (<jats:italic>I</jats:italic>) were described.