Synthesis and biological evaluation of boronic acid-containing phenstatin analogues

A series of boronic acid-containing benzophenones was synthesized by introducing a boronic acid as an acceptor-type functional group into the aromatic ring B of the phenstatin skeleton. Among the compounds synthesized, 4c in which a hydroxyl group on the aromatic ring B of the phenstatin was replaced by a boronic acid, exhibited significant cell growth inhibition and the GI(50) values toward B-16 and 1-87 cell lines are 0.013 mu M and 0.087 mu M, respectively.