As part of efforts to identify natural modulators of multi-drug-resistant breast cancer, Euphorbia mauritanica L. chloroform extract yielded four undescribed oxygenated diterpenes, including three nor-ent-abietanes, euphomauritanol C-E (1-3), and one polyacylated jatrophane, euphomauritanolide A (4), along with two knowns, helioscopinolide A (5) and enukokurin (6). The chemical structures and configurations of compounds were established by combination of HRMS, FTIR, and NMR spectroscopic tools along with experimental and calculated TDDFT-ECD. The cytotoxicity evaluation of isolated compounds against the MCF-7