Study On The Purification And Antioxidant Activity Of Polyphenols From Sargassum Fusiforme

Sargassum fusiforme is one of Chinese important seaweeds.S.fusiforme polyphenols have strong biological activities.In the present study,S.fusiforme harvest at Dongtou,Wenzhou as the raw material,S.fusiforme crude polyphenols are extracted and further purified to achieve four fractions.The IR analysis and the determinations of polyphenols content,hydroxyl content and antioxidant activity are performed for all products.The results are as follows.(1)S.fusiforme crude polyphenols is extracted by ethanol,removed impurity by chloform and hexane,and separated by ethyl acetate,the yield is 2.77±0.02%.The crude polyphenols are further purified via column chromatography and achieved four fractions PHL1 ? PHL2 ?PHL3and PHL4 eluted by ethyl acetate/methanol.The yields of four fractions are 17.65±0.67%?9.89±0.19%?7.17±0.08%?20.7±0.35%,respectively,and the total yield is 55.41±0.91%.(2)The IR and TLC analyses,the determinations of polyphenols andhydroxyl group contents are performed for crude polyphenols and four fractions.The polyphenols contents are 86.83±0.58% for crude polyphenols,and 91.36±0.76%,91.01±1.12%,88.67±0.99% and92.88±0.86% for PHL1?PHL2?PHL3?PHL4 which are a little increased than crude polyphenols.Total hydroxyl group content is733.3±11.84?g/mg for crude polyphenols.In four fractions,it is highest863.72±20.96?g/mg in PHL3,then 789.10±3.64?g/mg and770.64±25.93?g/mg in PHL1 and PHL2,the lowest 751.66±24.67?g/mg in PHL4.The adjacent trihydroxy content is 247.40±2.49?g/mg in crude polyphenols.In four fractions,it is the highest in PHL3(314.17±3.91?g/mg),then similar in PHL1(287.04±5.48?g/mg)and PHL2(250.47±2.88 ?g/mg)and the lowest in PHL4(184.86±9.34?g/mg).The ratio of adjacent trihydroxy content to total hydroxyl group content(P2/P1)is an important parameter for polyphenols.It is 33.74% for crude polyphenols,and 36.38% and 36.37% for PHL1 and PHL3,and lowest for PHL4(24.59%).(3)The antioxidant activities of crude polyphenols and four fractions are evaluated.PHL2 shows the highest total antioxidant capability(417.45±6.67?g/mg),then PHL1(391.38±3.45?g/mg)and PHL3(353.43±5.55?g/mg),whereas crude polyphenols(338.29±1.96?g/mg)and PHL4(338.36±13.54?g/mg)are the lowest.The DPPH clearance rate is the most potent for four fractions(93.3%~94.8%),than crudepolyphenols(90.3%),all better than Vitamin C(83.34%)and Vitamin E.