Figure 1.
Honokiol and its derivatives. Three novel anti-tumor derivatives of honokiol namely 3’- formylhonokiol, 5-formylhonokiol and 3’, 5-diformylhonokiol are prepared after treating the honokiol with chloroform in 35% sodium hydroxide solution in presence of tetrabutyl ammonium bromide as phase transfer catalyst under 50 °C for 3 h. Out of these derivatives 3’- formylhonokiol and 5-formylhonokiol are isomers. Among honokiol and its three C-formylation derivatives, 5-formylhonokiol displayed the strongest inhibitory ability on tumor cell lines.
