Study On Extraction,Optimization,Characterization And Antioxidant Activity Of Polysaccharides From Codonopsis Pilosula By Water

The species of Codonopsis pilosula?Dangshen?are perennial herbs mainly distributed throughout east,southeast,and Central Asia.Among the genus C.tangshen,C.lanceolata,and C.pilosula are the most well-known species.Documentarily,they have been used for a long time as traditional Chinese medicines.They play their physiological functions in invigorating the spleen,nourishing the lungs and blood,and generating fluid.Some species are also used as food materials in southern China and Southeast Asia,such as tea,wine,soup,plaster,and porridge.Codonopsis species were shown to be of great importance in Chinese medicine,due to their broad biological activities.C.pilosula is a significant herbal medicine in China and one of its major active ingredients is polysaccharides.In this study,the crude polysaccharide extracted from the roots of C.pilosula by hot-water extraction method?HWE?was named as HW-CPPs and characterized.The Box-Behnken design?BBD?combined with response surface methodology?RSM?was applied to optimize the extraction conditions according to single-factor experiments.The main results of the study are as follows:After extraction of the polysaccharides from C.pilosula,the samples were dialyzed at3500 Da cut-off for 48 h.The results revealed that HW-CPPs with molecular weight3.69×10⁴ reached a maximum of 13.606%when the optimum extraction process was 1:12.6g/ml?solid-liquid ratio?,72 mesh?practical size?at 60°C for 60 min.HW-CPPs were hydrolyzed into component monosaccharides and subsequently labeled with 1-phenyl-3-methyl-5-pyrazolone?PMP?,and then the labeled monosaccharide derivatives were separated by a reverse phase C₁₈ column and monitored by UV absorbance at 250 nm.The results showed that HW-CPPs acidic heteropolysaccharide and eight monosaccharide derivatives?mannose,rhamnose,glucuronic acid,galacturonic acid,glucose,galactose,xylose,and arabinose?have been well separated by HPLC under optimized conditions and the composition analysis of monosaccharides from HW-CPPs samples could be achieved using acid hydrolysis and a set of monosaccharide standards.Congo-red test,Circular dichroism assay?CD?,X-ray diffraction?XRD?,and fluorescence spectra were confirmed that HW-CPPs contained triple-helical spatial conformation and semi-crystallite shape with the existence of some impurities.The distribution of particle sizes,examined by dynamic light scattering and scanning electron microscopy,demonstrated the moderate formation of polydisperse aggregates.The morphological investigation,performed by electron microscopy scanning,indicated the self-organization of the HW-CPPs with a smooth fibrous texture.Moreover,the study explored the antioxidant activity analysis of HW-CPPs on the free radicals scavenging experiment of DPPH,ABTS⁺,hydroxyl radical,and reducing power assay.The results showed that C.pilosula polysaccharide has certain antioxidant activity in vitro.In summary,this study obtained a complete set of extraction,optimization,characterization,and biological activity assessment of C.pilosula polysaccharide,which has important application value for the comprehensive development of C.pilosula polysaccharide.