Synthesis of Alkyl Triphenylphosphonium Ostruthin Derivatives as Potential Cytotoxic Candidates

Abstract Ostruthin, isolated from Paramignya trimera , was used as a scaffold to design its alkyl triphenylphosphonium derivatives. With the optimal reaction conditions in hand, five alkyl triphenylphosphonium ostruthin derivatives ( 1 – 5 ) were synthesized. Ostruthin and its derivatives were tested for cytotoxicity against human PANC‐1 pancreatic, Hela cervical, and HepG2 liver cancer cell lines. Ostruthin and its hexyl and heptyl triphenylphosphonium derivatives ( 4 and 5 ) showed strong preferential cytotoxicity against PANC‐1 cells with the PC 50 values of 10.3 and 14.4 μM, respectively. In addition, compounds 4 and 5 also exhibited potent cytotoxicity towards HeLa cells with the IC 50 values of 24.8 and 18.5 μM, respectively. The hexyl triphenylphosphonium group in 4 was found to slightly enhance cytotoxicity against HepG2 cells. Further, the morphological changes and the live‐cell imaging result suggested the anticancer potential against HeLa cells of the synthesized ostruthin derivative 5 .