New Cytotoxic Premyrsinane-Type Diterpenes from Euphorbia aleppica Against Breast Cancer Cells.

Euphorbia is used in traditional medicine to remove warts, possibly due to its cytotoxic or antiviral effects. This study investigated its phytochemistry and bioactive compounds. Euphorbia aleppica from the Euphorbiaceae family was collected from Kuhdasht, Lorestan, Iran. Plant material was dried and ground. Extraction was performed by maceration using a dichloromethane-acetone solvent. After removing fatty contents, fractionation was done by open column chromatography. Based on the initial H-NMR spectra, fractions containing diterpenoid compounds were identified. The Sephadex column and HPLC performed isolation. The HPLC was done with a regular YMC silica column using a hexane: Ethyl acetate (70: 30) solvent. The selected sub-fractions were identified by one and two-dimensional corelative NMR spectra. Accurate mass spectra confirmed the molecular formula of the obtained structures. Cytotoxicity was assessed using a standard MTT assay against breast cancer cells. The NMR and mass analysis identified compound 1 as a newly described and compound 2 as a pre-defined compound as 3, 7, 15β-triacetyl-5α-tigliate-13(17)-α-epoxy-14-oxopremyrsinane and 3, 7, 14, 15, 17-pentaacetyl-5-tigliate-13(17)-epoxypremyrsinane, respectively. Compound 1 showed moderate cytotoxicity, and compound 2 exhibited a potent cytotoxic effect dose-dependently against MCF-7 and MDA-MB 231 breast cancer cells, probably because of 14-O-acetyl and 17-O-acetylated hemiacetal groups.