不同炮制工艺鲜竹沥多糖的化学特征及体外抗氧化活性比较

目的：比较鲜竹沥不同炮制品多糖的化学特征，并评估其体外抗氧化活性，为鲜竹沥物质基础研究提供理论依据。方法：分别采用苯酚-硫酸法、改良福林-酚试剂（Lowery）法、高效分子排阻色谱联用蒸发光散射检测器分析法（HPSEC-ELSD）、高效分子排阻色谱联用多角度激光散射与示差折光仪分析法（HPSEC-MALLS-RID）、扫描电子显微镜（SEM）对不同炮制工艺鲜竹沥多糖的化学特征进行多维度比较，采用1,1-二苯基-2-苦基肼基（DPPH）自由基清除能力检测试剂盒评价体外抗氧化活性。结果：干馏、火制和水提鲜竹沥的多糖含量、多糖的糖含量及蛋白含量有明显差异，特别是干馏法鲜竹沥多糖的蛋白含量和HPSEC-ELSD指纹图谱与其他两种炮制品的差异较大；进一步HPSEC-MALLS-RID分析表明，干馏法鲜竹沥多糖色谱峰1的相对分子质量远大于其他炮制品，且相对分子质量分布较其他炮制方法更分散；SEM分析发现，干馏法鲜竹沥多糖的表面及断面较其他炮制品更光滑。体外抗氧化活性检测显示，3种炮制品多糖均有一定的抗氧化活性，其中干馏法鲜竹沥多糖具有最强的抑制活性，水提法次之，火制法最弱。结论：不同炮制工艺不仅影...

Comparison of Chemical Characteristics and In Vitro Antioxidant Activity of Polysaccharides from Fresh Bamboo Juice Prepared by Different Processing Methods

Objective The aim of the study is to compare the chemical characteristics and evaluate the in vitro antioxidant activity of polysaccharides from fresh bamboo juice prepared by different processing methods, which will provide a theoretical basis for the substance-based research of fresh bamboo juice.Methods The chemical characteristics of polysaccharides from fresh bamboo juice prepared by different processing methods were analyzed using phenol-sulfuric acid method, modified Lowery method, high-performance size-exclusion chromatography coupled with evaporative light scattering detection (HPSEC-ELSD), high-performance size-exclusion chromatography coupled with multi-angle laser light scattering and refractive index detection (HPSEC-MALLS-RID), and scanning electron microscopy (SEM) for multi-dimensional comparison. The in vitro antioxidant activity was evaluated using the DPPH free radical scavenging capacity assay kit.Results The polysaccharide content, sugar content, and protein content of fresh bamboo juice prepared by dry distillation, calcination, and water extraction methods were significantly different, especially for the protein content and HPSEC-ELSD fingerprint of polysaccharides from dry-distilled bamboo juice. Further HPSEC-MALLS-RID analysis showed that the molecular weight of peak No. 1 in polysaccharides from dry-distilled bamboo juice was much higher than that of other processing methods, and the distribution of molecular weight was also more dispersed than that of other processing methods. SEM analysis revealed that the surface and section of polysaccharides from dry-distilled bamboo juice were smoother than those of the other processing methods. In vitro antioxidant activity test demonstrated that polysaccharides from the three processing methods exhibited certain antioxidant activity. Of which, polysaccharides from dry-distilled bamboo juice exhibited the strongest inhibitory effect, followed by polysaccharides from the water extraction method and the calcination method.Conclusion Different processing methods not only affect the content of polysaccharides in fresh bamboo juice, but also affect their chemical characteristics and biological activities. This study reveals the potential medicinal value of polysaccharides from fresh bamboo juice, and provides a scientific basis for polysaccharides as quality indicator in the processing of fresh bamboo juice.