Abstract: In order to improve the anti-tumor activity of baicalein,it was structurally modified.First,an amine methylene group is introduced to the 8-position by a mannich reaction,and then a different hydrophobic group is introduced to the 7-position (6-position) phenolic hydroxyl group by an acylation reaction.The target compound was evaluated for activity against MCF-7 tumor cells by the CCK-8 method.As a result,six target compounds were synthesized,and compound 2-6 are new compounds.Their structures were determined by a combination of ¹H NMR,¹³C NMR,MS and chemical methods.The chemical methods utilized the characteristics of the o-diphenol hydroxyl group of flavonoid，which could react with ruthenium chloride to confirm that the ester bond of the compounds was at the 7-position hydroxyl group.Activity experiments showed that the activity of the compound with an amine-methylene group that containing a nitrogen atom at the 8-position is stronger than the lead compound.And after the ester bond is introduced at the 7-position,the activity of most compounds becomes better.

Key words: baicalein, structural modification, mannich reaction, acylation reaction, structure confirmation, antitumor