N-邻羟苄基氨基酸的合成、表征及抑菌活性

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。

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

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 NaBH_4 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(CH_3)_2＞CH_3, CH_2CH(CH_3)_2＞H. The bromine atoms on the benzene ring of the title compounds have little effect on antibacterial activities to M.albicans and E.coli.