Studies On Structure And Bioactivities Of Ploysaccharides And Its Derivatives From Guangxi Wild Dendrobium Officinale

Dendrobium officinale has high medicinal value,so it has the reputation of "gold in medicine" and "life-saving fairy grass".Guangxi is rich in wild resources,but the wild Dendrobium officinale resources are endangered,important progress has been made in artificial cultivation of Dendrobium officinale,in order to further develop and apply Dendrobium officinale.In this paper,the structure analysis and activity study of Guangxi wild Dendrobium officinale polysaccharides were carried out.The crude polysaccharide was obtained by hot water extraction.The levels of three factors,extraction temperature,material-liquid ratio,and extraction time,were determined through single-factor experiments,and the optimal conditions for extraction rates were explored through response surface experiments.The Design-Expert software was used to obtain the extraction model.The crude polysaccharide was decolorized,deproteinized,and separated on a column,and passed through a DEAE-52 cellulose column and a Sephadex G-100 gel column,respectively.Finally,two polysaccharide components(DOP1 and DOP2)were separated and purified,and were analyzed by AFM,HPGPC,HPLC,GC-MS,NMR analysis of polysaccharide structure.For the first time,an oligosaccharide was isolated from Dendrobium officinale in Guangxi.The DOP1 was modified by sulfate and acetylation,and the degree of substitution was 1.2 and 0.64,respectively.The infrared spectrum showed corresponding characteristic peaks.Taking ascorbic acid as a control,three methods were used to evaluate the antioxidant activity.Using 5-fluorouracil as a control,use the MTT method to investigate the inhibitory effect on cancer cells to compare the activities of extracting polysaccharides and modifying polysaccharides.The clearance rate or inhibition rate is modified polysaccharide > crude polysaccharide > purified polysaccharide.For different antioxidant experiments or different cancer cells,sulfated modification and acetylated modification have different levels,showing different effects.This study through the extraction and activity research of wild Dendrobium officinale polysaccharides in Guangxi has important significance for the functional research and development and utilization of Dendrobium officinale polysaccharides,provides a reference for the development of Dendrobium officinale related products,and further explores the medicinal materials of the Guangxi Province Value and economic value lay the foundation.