Seaweed Sulfated Polysaccharides, Extraction And Purification Of The Degradation And Activity

Laminaria-polysaccharides are the main activity substance in Laminaria kelp,such as algin, fucoidan and laminaran.Fucoidan,the acid polysaccharides with sulfate ester,have many biological properties and pharmacological functions,such as immunity regulation,antitumor, antigrume,lower adipose,lower sugar,radio-protection,anti-mutation and anti-oxidation.This paper discussed the merits of LPS extraction and found an economical and simple method of purification of polysaccharides.By determining the best conditions of Ultrasonic degradation of LPS and analysis of polysaccharide degradation activity,two Oligosaccharides with higher activity were obtained.The polysaccharide sulfate was extracted from Laminaria japonica by water extraction and enzyme extraction,then,the extraction rate was compared.The crude LPS were purified elementarily,through extracted by CTAB and decolorized by macroporous resin.The optimum conditions of purification were conducted.The effects of power of ultrasonic,concentration of Laminaria polysaccharide sulfate,ultrasonic processing time on the degradation of Laminaria polysaccharide sulfate were studied by ultrasonic degradation.Through single factors and orthogonal experiments,the optimum conditions of ultrasonic degradation were conducted. Jointed with ultrasonic,H₂O₂ was used to degrade the polysaccharide sulfate,and the result was compared to that of H₂O₂.After degradation,the product was graded with ethanol.The antioxidant effects of L₃,L₅ were studied from three different experiments:eliminating superoxide anion free radical experiment,inhibiting auto and induced lipid per-oxidation in rate liver homogenate.MTT cell viability assay and Hoechst 33258 staining experiments were conducted to compare the growth inhibitory activity on tumor cell A549.The result showed that enzyme extracting method was more effective than that of water extraction,the extracting rate of crude LPS and pure LPS were increased by 85.9%and 43.6% respectively,compared with that of water extraction.The crude LPS were precipitated using CTAB as precipitant.Through orthogonal experiments,we obtained the optimal technological parameter:ratio of 1%LPS and 5%CTAB 3:2,precipitation time 6h,centrifugal time 12min. Decolorizing experiments were carried out by single experiment.The best conditions for discoloration were determined as follows:D315 resin,ratio of 1%LPS and resin was 100:1 (V/W),Time=6h,pH=5.0,T=40℃.The optimum conditions were as follows:power of ultrasonic 200W,concentration of Laminaria sulfate 4g/L,ultrasonic processing time 15min. Under the conditions,the degradation characteristic viscosity was 0.987mL/g,molecular weight was 46.4KD.Laminaria polysaccharide sulfate can be degraded effectively by ultrasonic,and the contents of polysaccharide and the SO₄^2-,structure were not changed.Ultrasonic degradation of polysaccharide 2h assisted H₂O₂ and H₂O₂ degradation 6h separate can obtain the same viscosity average molecular lower than 10000.After degradation,the activities of anti-oxidation and tumor cell growth inhibiting are all improved in different degree,thereinto,HSL₅ is superior to L₃ about anti-oxidant,but L₃ had more effective growth inhibitory activity on tumor cell.Conclusion:1.The enzymatic method is an efficient method of extraction of LPS.2.After extracted by CTAB and decolorized by macroporous resin,crude LPS can be purified effectively. 3.LPS can be effectively degraded by ultrasonic,after degraded,the activities of anti-oxidation and tumor cell growth inhibiting of degradation products are all improved.