本研究主要通过单因素和正交试验，探讨了朝鲜蓟叶多酚的最佳提取工艺，比较了大孔树脂纯化前后朝鲜蓟叶多酚提取物的抗氧化和抑菌活性的差异。结果表明，最佳提取工艺为：乙醇浓度70%，料液比1:20，超声时间40 min，该条件下多酚提取量为88.36 mg/g。通过9种大孔树脂静态吸附及解吸性能的比较，确定了NKA-2型树脂为朝鲜蓟多酚的最佳纯化树脂。经过大孔树脂纯化后，朝鲜蓟叶多酚的抗氧化能力显著增强，如对DPPH、ABTS+自由基清除的IC50值分别从82.79 μg/mL和251.30 μg/mL，降低到32.30±0.25 μg/mL、107.98±0.42 μg/mL。另外，纯化工艺还显著提高了朝鲜蓟叶提取物的抑菌效果，对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、白色念珠菌、绿脓杆菌和乳杆菌均有抑制作用。综上所述，该研究为朝鲜蓟叶多酚的提取、纯化和应用提供了科学依据和理论基础。

In this study, the optimal conditions for extracting polyphenols from artichoke leaves were investigated using single factor and orthogonal tests. The antioxidant and antibacterial activities of the polyphenol extracts from artichoke leaves before and after the purification by macroporous resins were compared. The results showed the optimal extraction conditions were: extraction solvent, 70% ethanol; sample/solvent ratio, 1:20 (g/mL); ultrasonic time, 40 min. Under these conditions, the total phenol content of the extract from artichoke leaves was 88.36 mg/g. Based on the comparison of static adsorption and desorption of nine macroporous resins, NKA-2 resin was found to be the best option for purification of the polyphenol extract. After such purification, the antioxidant activity of the purified polyphenol extract from artichoke leaves was significantly increased e.g. the IC50 values of 1-diphenyl- 2-trinitrobenzene hydrazine (DPPH) and 2, 2'-azino-bis(3-ethylbenzothiazoline-6- sulfonic acid) (ABTS) radical scavenging decreased to 32.30±0.25 μg/mL and 107.98 ± 0.42 μg/mL from 82.79 μg/mL and 251.30 μg/mL, respectively. In addition, the purification process significantly improved the antibacterial effect of the extract from artichoke leaves, including the inhibition of Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Monilia albican, Pseudomonas aeruginosa and Lactobacillus. In summary, this work provides a scientific basis and theoretical foundation for the extraction, purification and application of the polyphenols from artichoke leaf.

国家自然科学基金青年基金项目（31600274）；云南省应用基础研究计划面上项目（2018FB036）