Extraction, Purification, Structure And Bioactivity Of Polysaccharides From The Flower Of Tea

Tea flower is tea(Camellia sinensis) tree’s reproductive organ, which is a perennial herb, native to China. Tea flower contains a variety of beneficial ingredients, however, its development and utilization are not sufficient. Many scholars have confirmed that a variety of physiological functions of polysaccharides. few studies focus on the polysaccharide of tea flower(TFPS) at home and abroad. Therefore, in this paper, TFPS was studied, including extraction, purification, determination of antioxidant activity in vitro, liver protection in vivo and anti-tumor activity in vitro, and its structure.1. Using the flower of tea plant as material, the content of soluble sugars, tea catechins, and free amino acids in tea flower were analyzed by using high performance liquid chromatography (HPLC). Tea flower contained216.85mg/g of soluble free sugars, and its corolla, stamen and pistil (F-1) and its receptacle, sepal and pedicel (F-2) contained250.94and112.65mg/g of soluble free sugars, respectively. Tea flower contained37.03mg/g of tea catechins, and the content of F-2(46.90mg/g) was higher than that of F-1(30.88mg/g). As for free amino acids, tea flower contained16kinds of free amino acids including L-theanine, and its content of total free amino acids was10.87mg/g. Although less kinds of free amino acids including L-theanine were detected in F-2, its content (16.47mg/g) was notably higher than that of F-1(10.59mg/g).2. Take tea flower powder into85%ethanol to defat and remove pigment, and then extracted in90℃water bath for3times, centrifuged and take supernatant, concentrated by ethanol precipitation, freeze dried and crude TFPS was obtained, the yield was6.67-6.89%. The crude TFPS was purified by anion-exchange chromatography of DE-52, and3components named TFPS-1, TFPS-2and TFPS-3were obtained. Basic physicochemical characterization of crude TFPS, TFPS-1, TFPS-2and TFPS-3were determined by using the methods of chemistry and physics. The polysaccharides contents were29.80%,63.90%,34.94%and28.99%, respectively; the protein contents were5.05%,2.53%,2.37%and2.31%, respectively; the uronic acid contents were22.75%,1.40%,37.69%and31.26%, respectively and the sulfate contents were1.45%,2.63%,0.84%and1.76%, respectively.3. Antioxidant activities in vitro of crude TFPS, TFPS-1, TFPS-2and TFPS-3were measured by using the chemical methods. Results showed that crude TFPS, TFPS-1, TFPS-2and TFPS-3could scavenge DPPH·, scavenge free radicals of O2, scavenge free radicals of HO, chelate Fe2+and reduce Fe3+in vitro. Crude TFPS exhibited strong antioxidant activities in vitro; TFPS-1showed high activity on scavenging DPPH-and chelating Fe2+; TFPS-3showed high activity on scavenging free radicals of O2and HO. Liver protection in vivo of crude TFPS were determined by using the animal model experiments. Results showed that treatment of crude TFPS can protect liver from injuring induced by CCl4effectively.; Administration of middle dose of crude TFPS exhibited the best protection, could inhibit significantly the activity of ALT and AST in serums, enhance significantly the value of SOD and GSH-Px in liver and inhibit the formation of MDA in liver.The inhibition effects of crude TFPS, TFPS-1, TFPS-2and TFPS-3on the growth of BGC-823cells were evaluated in vitro by MTT assay. Results showed that TFPS-1and TFPS-3exhibited stronger inhibit effects, when the concentration was200μg/ml, incubated for72h, the inhibition were82.60%and83.73%, respectively.4. Monosaccharide composition and molar ratio of crude TFPS, TFPS-1, TFPS-2and TFPS-3were analyzed by Gas chromatography(GC). They were Rhamnose:Arabinose: Fucose:Xylose:Mannose:Glucose:Galactose=10.17:49.52:2.58:1.49:2.68:11.54:22.04, Arabinose:Fucose:Xylose:Mannose:Glucose:Galactose=14.84:2.64:12.16:6.87:45.39:18.08, Rhamnose:Arabinose:Galactose=11.19:55.16:33.65, and Rhamnose:Arabinose: Galactose=20.95:53.34:20.71, respectively.The infrared absorption spectroscopy (IR) of crude TFPS, TFPS-1, TFPS-2and TFPS-3showed that they were polysaccharide.Using high performance of gel filtration chromatography (HPGFC) to detect the purity of TFPS-1, TFPS-2and TFPS-3, Results showed that TFPS-3was purified polysaccharide, and its molecular weight was381.33KDa.