摘要
以L-谷氨酸为起始原料,经邻苯二甲酸酐保护、酰化开环、肼解脱保护等反应合成了7种茶氨酸类似物,结构经EA、IR、1HNMR、13CNMR和MS进行了确认,并测定了其清除DPPH自由基和羟自由基活性。结果表明:2-氨基-5-氧代-5-[(4-羟基苯基)氨基]戊酸清除自由基活性最强,0.002 mol/L时清除DPPH自由基率为90%,0.004 mol/L时清除羟自由基率达95%;2-氨基-5-氧代-5-[(4-氨基苯基)氨基]戊酸次之。由此可见,茶氨酸类似物中5位连有苯基或所连苯基对位有供电子基团时,可提高其清除DPPH自由基和羟自由基活性,且随对位所连基团供电性的提高,清除活性增强。
7 kinds of analogs of theanine were synthesized from L-glutamic acid via protection by phthalic anhydride, opening ring by acylation, and deprotection by hydrazinolysis. The products were identified by EA, IR, 1HNMR, 13 CNMR and MS spectra, and the activity of scavenging DPPH free radical and hydroxyl free radical was tested. The results indicate that 2-amino-5-[ （4-hydroxyphenyl） amino]-5-oxopentanoic acid was the best analog to scavenge free radicals; the clearance rate to DPPH free radical was 90% at 0. 002 mol/L and the clearance rate to hydroxyl free radical was 95% at 0. 004 mol/L. It was followed by 2-amino-5- [ （4-aminophenyl） amino ] -5-oxopentanoic acid. This shows that it could enhance the ability of scavenging DPPH free radical and hydroxyl free radical when the substituent group on 5 was phenyl or electron donating groups at para-position, and that, with the ability of electron donating at para-position being enhanced, the activity of scavenging free radicals became stronger.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2013年第11期1307-1311,共5页
Fine Chemicals
