【摘要】 研究新型席夫碱[(E)-1-(3,5-二氯-2-羟基-4-甲氧基苯基)亚乙氨基]乙酸乙酯的合成、表征及生物活性。以乙腈为溶剂,3,5-二氯-2-羟基-4-甲氧基苯乙酮与甘氨酸乙酯物质的量比为1:3,反应温度和时间分别为25℃和1 h时,最大反应收率为90.97%。采用UV,IR,LCMS,1H NMR,荧光光谱及X射线单晶衍射等方法表征了产物的分子及晶体结构。紫外可见吸收光谱表明:目标化合物的甲醇溶液在330 nm和410 nm处分别出现烯醇式和酮式亚胺互变异构吸收峰;在甲醇、N,N-二甲基甲酰胺(DMF)、二氯甲烷和氯仿溶液中具有蓝紫色荧光,最佳荧光激发和发射波长分别为332~372 nm和451~499 nm,且随溶剂极性增大,荧光激发峰红移;目标化合物晶体属单斜晶系,空间群为P21/c,β=91.131(5)o,a=4.571 1(18)?,b=30.302(12)?,c=10.602(4)?,V=1 468.2(10)?3,Dc=1.448×103kg·m-3,Z=4,R1=0.058 9,w R2=0.123 2;具有一定抗氧化作用,浓度为62.50 mg·L-1时,对1,1-二苯基-2-苦基肼(DPPH)自由基清除率达27.95%;对大肠杆菌和金黄色葡萄球菌具有一定抑制作用,最低抑菌浓度(MIC)均为1.0×10-6mol·L-1;对铜绿假单胞菌基本无抑制作用。更多还原

【Abstract】 The synthesis, characterization and bioactivity of a new Schiff base ethyl [(E)-1-(3, 5-dichloro-2- hydroxy-4-methoxyphenyl)ethylidene]aminoacetate was studied. The maximum yield 90.97% was obtained by the reaction of 3, 5-dichloro-2-hydroxy-4-methoxyacetophenone with glycine ethyl ester hydrochloride in 1: 3molar ratio under room temperature in acetonitrile for 1 h. The molecular and crystal structure of the product was characterized by UV, IR, LCMS,1H NMR, fluorescence spectra and X-ray single crystal diffraction, respectively.The UV spectra of the target compound in methanol solution indicated that the maximum absorption of the π→π* electron transition of the enol and keto tautomer of the target compound appeared at 330 nm and 410 nm, respectively. It has blue or violet fluorescence in methanol, DMF, dichloromethane and chloroform solution, and the maximum excitation and emission wavelength was at 332-372 nm and 451-499 nm, respectively. The target compound was crystallized in monoclinic system, space group P21/c, with β = 91.131(5)o, a = 4.571 1(18) ?,b = 30.302(12) ?, c = 10.602(4) ?, V = 1 468.2(10) ?3, Dc= 1.448×103kg· m-3, Z = 4, R1= 0.058 9, w R2= 0.123 2.It was a mild antioxidant, the maximum scavenging rate of 1, 1-diphenyl-2-picryl hydrazyl(DPPH) free radicals was 27.95% under the concentration of 62.50 mg· L-1. The target compound had antibacterial activity against Escherichia coli and Staphylococcus aureus, both minimal inhibitory concentration(MIC) were 1.0×10-6mol·L-1, but had no antibacterial activity against Pseudomonas aeruginosa.更多还原