The synthesis and anticancer effects of a range of natural and unnatural hop β-acids on breast cancer cells

► The anticancer activity of lupulone 1 and related congeners has been undertaken. ► Activity against breast cancer cell lines MCF-7 and MDA-MB-231 was measured. ► Novel lupulone derivatives were more toxic to MDA-MB-231 cell lines. ► MDA-MB-231 cell lines are characterised by an aggressive phenotype. ► Novel lupulone derivatives were very efficient at killing cancer cells by apoptosis.