N-邻羟苄基氨基酸的合成、表征及抑菌活性

Synthesis,Characterization and Antibacterial Activity of N-o-Hydroxybenzyl-Amino Acids

将水杨醛、溴代水杨醛及二溴代水杨醛分别与4种L-α-氨基酸进行缩合反应生成相应席夫碱,不经分离直接加硼氢化钠将其还原制得N-邻羟苄基氨基酸类化合物(3)。化合物的结构经IR、1H NMR和元素分析测试技术表征确认。测得化合物3在质量分数为0.05%时,对金黄色葡萄球菌的抑菌率为100%,对白色念珠菌有较强的抑菌活性,对大肠杆菌有一定的抑菌活性。氨基酸的碳链R的结构是影响化合物抑菌活性的关键因素,不同烷基R对白色念珠菌和大肠杆菌抑菌活性增强的顺序为CH(CH3)2>CH3,CH2CH(CH3)2>H,苯环上引入溴原子对目标化合物的抑菌活性影响不明显。

Twelve o-hydroxybenzyl-amino acids were synthesized.Salicylaldehyde and its two-derivatives were respectively condensed with each of 4 L-α-amino acids in the presence of sodium hydroxide to obtain amino acid Schiff bases,which were subsequently reduced by NaBH4 to produce o-hydroxy-benzyl-amino acids（3）.The structures of the products were confirmed by IR,1H NMR and elemental analysis.The result of preliminary bioassay shows that these compounds are highly effective in S.aureus inhibition at 0.05%（mass concentration） with an inhibitory ratio of 100% and have antibacterial activities to M.albicans and E.coli to some extent.Structure of the substituent R has important effect on the antibacterial activity of o-hydroxy-benzyl-amino acids.The effects of different alkyl R on antibacterial activities to M.albicans and E.coli show the following order CH（CH3）2CH3,CH2CH（CH3）2H.The bromine atoms on the benzene ring of the title compounds have little effect on antibacterial activities to M.albicans and E.coli.