The aim of this study was to investigate the effects of microwave ultrasonic-assisted extraction (MUAE) on the content, structure, and biological functions of Brassica rapa L. polysaccharide (BRP). Response surface methodology (RSM) was used to optimize the parameters of MUAE, and it obtained a polysaccharide with yield of 21.802%. Then, a neutral polysaccharide named BRP-1-1 with a molecular weight of 31.378 kDa was isolated and purified from BRP using DEAE-650 M and Sephadex G-100. The structures of the BRP-1-1 were elucidated through a combination of FT-IR, GC-MS, NMR, and methylation analysis. The results showed that BRP-1 consisted of mannose (Man) and glucose (Glu) in a molar ratio of 7.62:1. The backbone of BRP-1-1 mainly consisted of →6)-α-D-Glup-(1→4-β-D-Glup-(1→2)-α-D-Manp-(1→2)-α-D-Glup-(1→, the branch was [T-α-D-Manp-(1]_n→. BRP-1-1 intervention significantly inhibited α-glucosidase activity; an inhibition rate of 44.623% was achieved at a concentration of 0.5 mg/mL. The results of the in vitro biological activity showed that BRP-1-1 has good antioxidant and hypoglycemic activity, suggesting that BRP-1-1 could be developed as a functional medicine.

中文翻译：

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油菜多糖的分离、结构鉴定、抗氧化和降血糖活性。

本研究的目的是研究微波超声辅助提取 (MUAE) 对芸苔的含量、结构和生物学功能的影响。L. 多糖 (BRP)。采用响应面法(RSM)优化MUAE的参数，得到多糖，收率为21.802%。然后，使用DEAE-650 M和Sephadex G-100从BRP中分离纯化出分子量为31.378 kDa的中性多糖BRP-1-1。通过结合 FT-IR、GC-MS、NMR 和甲基化分析阐明了 BRP-1-1 的结构。结果表明，BRP-1由甘露糖(Man)和葡萄糖(Glu)组成，摩尔比为7.62:1。BRP-1-1的骨架主要由→6)-α-D-Glup-(1→4-β-D-Glup-(1→2)-α-D-Manp-(1→2)-组成α-D-Glup-(1→, 分支为 [T-α-D-Manp-(1] _n→。BRP-1-1干预显着抑制α-葡萄糖苷酶活性；浓度为 0.5 mg/mL 时抑制率为 44.623%。体外生物活性结果表明，BRP-1-1具有良好的抗氧化和降血糖活性，提示BRP-1-1可开发为功能性药物。