Previously, the authors conducted phytochemical investigations of the aerial parts of Larrea tridentata and reported triterpene glycosides and lignan derivatives. In continuation of the preceding studies, 17 lignans and lignan glycosides (1-17) were isolated, including seven new compounds (1-7). Herein, the structure of the new compounds was determined based on spectroscopic analysis and enzymatic hydrolysis. The cytotoxicity of 1-17 against HL-60 human promyelocytic leukemia cells was examined. Compounds 4-11 and 14-16 were cytotoxic to HL-60 cells, with IC50 values in the range of 2.7-17 μM. Compound 6, which was the most cytotoxic among the unprecedented compounds, was shown to induce apoptotic cell death in HL-60 cells.
Keywords: HL-60 cell; Larrea tridentata; Zygophyllaceae; aerial part; apoptosis; cell cycle; cytotoxicity; lignan; lignan glycoside.