Two novel alkaloids named oleraciamide A (1) and oleraciamide B (2) were isolated from Portulaca oleracea L., and spectroscopic methods including 1D and 2D nuclear magnetic resonance and high-resolution electrospray ionisation quadrupole-time of flight mass spectrometer spectrometry techniques are employed to determine their structures. Oleraciamide A (1) was evaluated no cytotoxicity at concentrations up to 80 μM over 72 h against human adipose-derived stem cells (hADSCs) by CCK-8 method. © 2017 Informa UK Limited, trading as Taylor & Francis Group.