Synthesis of demethylxanthohumol, a new potent apoptosis-inducing agent from hops.

Starting from commercially available phloracetophenone (= 1-(2,4,6-trihydroxyphenyl)ethanone), we synthesized demethylxanthohumol (4), a derivative of xanthohumol, devoid of 6'-O-methyl group. Both are prenylchalcones derived from hops (Humulus lupulus). The synthesis was accomplished by an aldol condensation between MOM-protected acetophenone 2 and MOM-protected benzaldehyde 3. The resulting demethylxanthohumol (4) displayed antiproliferative properties. Demethylxanthohumol (4) induced also apoptosis via the mitochondrial pathway in BJAB cells (Burkitt lymphoma cell line) and in primary lymphoblasts of childhood acute lymphoblastic leukemia (ALL).