【摘要】 在对甲苯磺酸为催化剂,N,N-二甲基乙酰胺为溶剂,环己烷为带水剂的体系中,肉桂醛与L-抗坏血酸加热回流得到标题化合物,产率41%。1HNMR的数据表明,产物为两个非对映异构体组成的混合物。用分光光度法研究了产物清除羟基自由基、超氧阴离子自由基和DPPH自由基的能力。结果表明,当受试物的物质的量浓度相同时,产物清除上述3种自由基的能力与L-抗坏血酸基本相当,略比TBHQ强。用MTT法测试了产物对大肠杆菌、枯草芽孢杆菌和铜绿假单胞菌的抗菌作用。结果表明,产物的抑菌活性相当于或略高于肉桂醛,比L-抗坏血酸更强。更多还原

【Abstract】 A novel ascorbic acid acetal,5,6-O-styrylmethylene-L-ascorbic acid,was synthesized by refluxing cinnamaldehyde(1.32 g,10 mmol)and L-ascorbic acid(2.87 g,15 mmol)in the presence of p-toluene sulfonic acid(0.19 g,1 mmol)used as the catalyst,N,N-dimethyl acetamide(8 mL)used as the solvent and cyclohexane(8 mL)used as the water-carrying agent for 2.5 h in 41% yield.5,6-O-styrylmethylene-L-ascorbic acid was obtained as a mixture of two diastereomers in a molar ratio of 9∶1 based on the 1HNMR spectroscopic analysis.The scavenging activity of 5,6-O-styrylmethylene-L-ascorbic acid on removing hydroxyl free-radical,superoxide anion free-radical and DPPH free-radical was tested,and compared with that of L-ascorbic acid and TBHQ by spectrophotometry.It was found that the scavenging activity of 5,6-O-styrylmethylene-L-ascorbic acid was stronger than that of TBHQ,and was almost equal to that of L-ascorbic acid,when the molar concentration of the tested samples was the same.The anti-microbial activity of 5,6-O-styrylmethylene-L-ascorbic acid was investigated by MTT assay.Minimal inhibitory concentration(MIC)data showed that 5,6-O-styrylmethylene-L-ascorbic acid had significant inhibition effect on the growth of Escherichia coli,Bacillus subtilis and Pseudomonas aeruginosa.更多还原