肉桂酸植物甾醇酯的酶法合成及对DPPH·的清除作用

Enzymatic Synthesis and Scavenging DPPH·Activity of Cinnamic Acid Pphytosterol Ester

在非水相反应体系中,通过脂肪酶催化合成肉桂酸植物甾醇酯。采用薄层色谱和高效液相色谱对产物进行分析。通过优化实验,确定最佳反应条件为:在5 mL 2-甲基四氢呋喃中,肉桂酸乙酯与植物甾醇底物摩尔比1∶ 1,反应温度60 ℃,Novozym435脂肪酶添加量120 mg(肉桂酸乙酯0.5 mmol),在此反应条件下,反应120 h后肉桂酸植物甾醇酯的产率可达76.34%。通过考察产物对自由基的清除能力,发现肉桂酸植物甾醇酯对DPPH·具有一定的清除能力,IC 50 值为0.31 mg/mL,抗氧化能力强于底物,且通过酯化改善了植物甾醇的溶解性与稳定性。

The cinnamic acid phytosterols ester was synthesized by lipase in non-aqueous system. Thin layer chromatography and high performance liquid chromatography (HPLC) were adopted to analyze the product. Through experimental optimization, the optimum reaction conditions were determined as follows: dimethyltetrahydrofura was 5 mL, molar ratio of ethyl cinnamate to phytosterol was 1∶ 1, reaction temperature was 60 ℃, Novozym 435 lipase addition was 120 mg (ethyl cinnamate 0.5 mmol), reaction time 72 h. Under these conditions, the conversion rate of cinnamic acid phytosterol ester can reach 76.34% 120 h later. By examining the scavenging free radical ability of the product, it was found that cinnamic acid phytosterol ester had certain scavenging ability to DPPH·, with IC 50 value of 0.31 mg/mL. It was confirmed that the antioxidant capacity was stronger than that of the substrate, and the solubility and stability of phytosterol was improved by esterification.