The Difference in Cytotoxic Activity between Two Optical Isomers of Gelsemine from Gelsemium elegans Benth. on PC12 Cells

Two optical isomers, +/− gelsemine (1, 2), together with one known compound were isolated from the whole plant of G. elegans. The structures of the separated constituents were elucidated on 1D and 2D (1H-1H COSY, HMBC, HSQC) NMR spectroscopy and high-resolution mass spectrometry (HRMS). The isolated alkaloids were tested in vitro for cytotoxic potential against PC12 cells by the MTT assay. As a result, (+) gelsemine (compound 1) exhibited cytotoxic activity against PC12 cells with an IC50 value of 31.59 μM, while (−) gelsemine (compound 2) was not cytotoxic.