Abstract:

A series of 5-chloro-o-hydroxyphenyl amino acid esters schiff bases was designed and synthesized by the condensation of chlorinated salicylaldehyde with amino acid esters including phenylalamine methyl(ethyl) ester, leucine methyl(ethyl) ester and glycinate methyl(ethyl) ester, which were subjected to further reduction form 5-chloro-o-hydroxybenzyl amino acid esters. The structures of these compounds were characterized by IR, ¹H NMR and elemental analysis. The antibacterial activity assay indicates that these compounds resist different bacteria to different degrees. The result of preliminary bioassay shows that at a mass concentration of 0.01%, the inhibitory rate of the 5-chloro-o-hydroxyphenyl amino acid esters schiff base against Escherichia coli is over 90% and the inhibitory rate of the 5-chloro-o-hydroxybenzyl amino acid esters against Staphylococcus aureus is also over 90%. In addition, the inhibitory rate of 5-chloro-o-hydroxybenzyl phenylalamine ester against Staphylococcus aureus can be as high as 98%.

Key words: chloro-o-hydroxyphenyl amino acid ester schiff base, synthesis, antibacterial activity