Extraction,Purification,structure Analysis And Antioxidant Activity Of Polysaccharide From Garlic Bolt

Garlic bolt is a plant of the genus allium in the liliaceae family.The plant poly-phenols with high content in the garlic bolt have the function of promoting blood circulation,anticancer,bactericidal and so on,and have a wide range of pharmacolo-gical activities.Garlic blot is widely planted in China,and its output and export volume are large.The research on the planting,storage and processing methods of the garlic bolt is mainly focused on.There is no detailed literature report on the rese-arch on the polysaccharide of the garlic bolt at home and abroad.The researches on the planting,storage and processing methods of the garlic bolt have been mainly focused by domestic and foreign scholars,while the studies on the structure of the polysaccharide of the garlic bolt have been rarely reported.Based on the previous study,we found that the crude polysaccharides of garlic bolt had significant antio-xidant activity.The purified polysaccharide was obtained by extraction,separation and purification,and its structure was identified and its antioxidant activity was eval-uated,which provided theoretical basis and data support for the development of high value-added products of garlic bolt and their application in the fields of medicine and health care products.The main findings are as follows:(1)Extraction and purification of polysaccharides from garlic boltIn this part of the experiment,polysaccharides were extracted from garlic bolt by water extraction and alcohol precipitation,and the total polysaccharides were obt-ained.The polysaccharides yield was 1.45%by phenol sulfuric acid method,protein was removed by Sevage reagent,and protein clearance was 75.74%by coomassie blue method.The crude polysaccharide was obtained by removing pigment by hyd-rogen peroxide.Five components were obtained by DEAE anion exchange chroma-tegraphy,namely GDLD-0,GDLD-1,GDLD-2,GDLD-3 and GDLD-4.The results showed that the polysaccharides of the five components did not contain proteins or nucleic acids.Due to the large amount of GDLD-0 collected and its good water solu-bility,the refined polysaccharide GDLL was isolated and purified by Sephacryl gel method.(2)Structural identification of polysaccharides from garlic boltThe GDLD-0,GDLD-1,GDLD-2 and GDLD-4 were analyzed by infrared spectroscopy.The results showed that each of the four components contained charac-teristic absorption peaks of polysaccharides.The monosaccharides and molar ratio of the refined polysaccharide GDLL were analyzed by high performance liquid chromatography(HPLC)derived from the PMP column:galactose:glucose:arab-inose=4.36:73.29:1.70.GC-MS results showed that the connection modes of glu-coside bonds in GDLL were→5)-Araf-(1→,Glcp-(1→,→4)-Galp-(1→,6)-Glcp-(1→,→6)-Glcp-(1→and→4,6-Galp-(1→.Their percentages were 0.71%,4.87%,86.29%,1.17%and 6.95%.Combining infrared spectroscopy,monosac-charide composition and methylation results,the structural units of GDLL were analyzed by NMR spectroscopy as follows:#12(3)Antioxidant activity of polysaccharides from garlic boltIn this part of the experiment,the antioxidant activity of crude polysaccharides from garlic bolt and purified polysaccharides GDLD-0 and GDLL were studied in vitro.The effects of Vc and GDLL on ABTS free radicals,DPPH free radicals,metal ion chelation and superoxide anion free radicals were compared to evaluate the antioxidant capacity of crude polysaccharide,GDLD-0 and GDLL in vitro.The exp-erimental results showed that under the same conditions,the successively antioxi-dant capacity was crude polysaccharide>GDLD-0>GDLL.The possible reason is that crude polysaccharides contain a variety of homogeneous polysaccharides and other chemical components.