Two new alkaloids, named dehydrostenine A (1) and B (2), were isolated from the roots of Stemona sessilifolia (Miq.) Miq. Their structures were elucidated by comprehensive NMR spectroscopy and X-ray single-crystal diffraction experiment. Anti-acetylcholinesterase activities of compounds 1 and 2 were also tested, but did not show significant activity. © 2017 Phytochemical Society of Europe