Magnolol and honokiol,an active monomer from natural products,have shown superior pharmacological activities in anti-inflammation and anti-tumor proliferation,but the cytotoxicity limits their use.It prompted researchers to modify its structure to reduce the cytotoxicity while maintaining or even increasing the efficacy.Six derivatives were synthesized by introducing ester group,acylhydrazide and 1,3,4-oxadiazole at phenolic hydroxyl groups of magnolol and honokiol,of which five derivatives were synthesized for the first time.The structures of six compounds were analyzed by UV,IR,MS,NMR,and the absolute configurations of honokiol ester were determined according to the crystal structure.The in vitro cytotoxicity,anti-inflammatory and anti-tumor activities of derivatives were evaluated.It showed that the cytotoxicitiy of derivatives were significantly reduced when compared with magnolol and honokiol,the inflammatory mediators NO,IL-1β,and TNF-α were also inhibited by the derivatives,the anti-tumor research revealed antiproliferative effects of derivatives on human breast cancer(MCF-7),human hepatoma(HepG2) and human NSCLC(H1299,A549).In conclusion,this study provides certain reference values on structure modification of natural products for reducing cytotoxicity and improving pharmacological activities.