基于石斛中多糖含量较高，近年来国内外学者对石斛多糖的结构以及活性的研究逐渐深入，本综述对石斛多糖的单糖组成、糖苷键、乙酰基与分支度等结构进行了整理，对石斛多糖在抗氧化、免疫调节、抗糖尿病等活性方面的作用机制进行了总结。本文计算了具有抗氧化活性的石斛多糖清除DDPH自由基的EC50值，从具有抗氧化活性的石斛多糖单糖组成与相对丰度的角度出发，建立了随机森林模型。该模型预测了石斛多糖抗氧化活性的高低，模型预测准确度为70.00%。研究表明，对石斛多糖有无抗氧化活性影响最大的单糖为葡萄糖，石斛多糖抗氧化活性的高低与甘露糖和半乳糖的线性关系以及甘露糖与阿拉伯糖的线性关系具有相关性。本文对探究不同结构石斛多糖活性的定性与定量关系提供一定了的参考。

Based on the high content of polysaccharides in Dendrobium, the structure and activity of Dendrobium polysaccharides have been studied deeply in recent years. In this review, the monosaccharide composition, glycoside bond, acetyl group and branching degree of Dendrobium polysaccharides have been sorted out. The mechanism of activity of Dendrobium polysaccharides in antioxidant, immunomodulatory and anti-diabetic activities has been summarized. This paper calculated the EC50 value of free radicals scavenging DDPH Dendrobium polysaccharides with antioxidant activity, and established a random forest model from the point of view of the composition and relative abundance of polysaccharides monosaccharides of Dendrobium officinale with antioxidant activity. The model predicted the antioxidant activity of Dendrobium polysaccharides, and the accuracy of the model was 70.00%. The results showed that the monosaccharide which had the greatest influence on the antioxidant activity of Dendrobium polysaccharides was glucose. The linear relationship between the antioxidant activity of Dendrobium polysaccharides, mannose and galactose and the linear relationship between mannose and arabinose was related. This paper provides a reference for exploring the qualitative and quantitative relationship between polysaccharide activity of Dendrobium officinale with different structures.

广东省基础与应用基础研究基金项目（2019A1515011283）；广州市科技计划项目（202002030383）；广州市对外合作项目（201807010056；201907010005）