Synthesis and antibacterial activity of water-soluble limonin benzoylhydrazone derivatives

As a compound rich in citrus plants, limonin has a wide range of biological activities, but its practical application is limited because of its poor water solubility.In this paper, eight new compounds 7a-7h were designed and synthesized by introducing benzoyl hydrazone at the carbonyl position of limonin.The results showed that the water solubilities of all compounds were higher than that of limonin, especially 7a, 7d, 7e and 7f.In addition, the experiment showed that compounds 7d and 7e with substituted hydroxyl groups at the interposition and para-position of the benzene ring had strong antibacterial effects against Escherichia coli and Staphylococcus aureus, and that compound 7e had the best activity, with minimum inhibitory concentrations of 0.31 mg/mL and 1.25 mg/mL, respectively.And compound 7e had better antibacterial activiy in E.coli than sodium benzoate.