A new alkaloid, termed scopariaine A (1), was obtained from the whole plant of Scoparia dulcis L. The new structure was established by applying various spectroscopic methods including 1D (1H-,13C-NMR), 2D-NMR (HMBC, HSQC) and high resolution electrospray ionization mass spectrometry (HR-ESI-MS). Scopariaine A (1) was tested for its protective effect on attenuating palmitate-induced viability at 5, 10 and 25 μM. The results showed that the cell viability was significantly increased in palmitic acid combined with scopariaine A treated H9C2 cells. © 2021 ACG Publications.