Two new (1 and 2) and two known arylbenzofuran lignans (3 and 4) were isolated from the seeds of Arctium lappa. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–4 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results revealed that compound 3 showed good inhibition with IZD of 13.5 ± 1.5 mm), and compounds 1, 2, and 4 showed weak inhibition with IZD of 9.6 ± 1.0, 11.6 ± 1.2, and 10.8 ± 1.2 mm, respectively. Compounds 1–4 were also tested for the antioxidant activity, and they show good antioxidant activity with an IC50 values of 4.38, 4.22, 3.96, and 4.15 μg/mL, respectively.

中文翻译：

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牛蒡种子中芳基苯并呋喃木脂素及其生物活性

从牛蒡种子中分离出两种新的（1 和 2）和两种已知的芳基苯并呋喃木脂素（3 和 4）。它们的结构是通过光谱方法阐明的，包括广泛的 1D 和 2D NMR 技术。评估了化合物 1-4 的抗甲氧西林金黄色葡萄球菌（抗 MRSA）活性。结果表明，化合物3显示出良好的抑制作用，IZD为13.5±1.5mm)，化合物1、2和4显示出弱抑制，IZD分别为9.6±1.0、11.6±1.2和10.8±1.2mm。还测试了化合物 1-4 的抗氧化活性，它们显示出良好的抗氧化活性，IC50 值分别为 4.38、4.22、3.96 和 4.15 μg/mL。