Three new alkaloids, gelsebanine ( 1), 14 alpha-hydroxyelegansamine ( 2), and 14 alpha-hydroxygelsamydine ( 3), and a new extraction artifact, gelsebamine ( 4), together with 12 known alkaloids, were isolated from the stems and leaves of Gelsemium elegans. The structures of 1-4 were determined by spectroscopic methods, especially 2D NMR techniques. Compounds 1-4 were evaluated for cytotoxic activity against four tumor cell lines, and gelsebamine ( 4) selectively inhibited the A-549 human lung adenocarcinoma cell line.