分离、纯化了甜叶菊生物发酵制剂SC3的强抗氧化活性成分,包括以清除DPPH自由基能力为活性跟踪指标,选用石油醚、乙醚、乙酸乙酯和正丁醇等不同极性溶剂进行萃取分部,将得到的甜叶菊生物发酵制剂Scs强抗氧化活性成分用GF254薄层色谱分离纯化其抗氧化主活性成分,最终采用GC-MS对其进行结构鉴定。结果表明,SC3的5种溶剂萃取部在0.0066%、0.0132%和0.0198%浓度条件下,以乙醚部和乙酸乙酯部的DPPH自由基清除率最高,其中,从乙醚部分离得到的C1、C2、C3、C4四种抗氧化活性组分对DPPH自由基的清除能力分别为24.95%、10.30%、75.12%和77.49%。后对其活性最强的C3、C4两组分进行结构鉴定,确认C3为邻苯二酚,推断C4为3-异丙氧基-5-甲基苯酚。提示多酚类物质是SC3强抗氧化作用的主要物质基础。

This research was to separate,purify and structurally identify the high antioxidant compositions from a fermentation preparation of a Chinese plant Stevia rebaudiana(SC3).The DPPH assay was used as an antioxidant activity monitoring parameter,and different fractions were obtained with different polar solvents such as petroleum ether,ether,ethyl acetate and normal butyl alcohol.The main antioxidant components from the highest antioxidative fractions were separated and purified by a GF254 TLC assay,and their chemical structures were further analyzed by GC-MS.The results indicated that scavenging effect of the ether fraction and ethyl acetate fraction from SC3 on DPPH radical was the highest at the concentrations of 0.006 6%,0.013 2% and 0.019 8% respectively.Four main antioxidative components C1,C2,C3,C4 were separated by ether,fraction and their scavenging effect on DPPH radical reached 24.95%,10.30%,75.12% and 77.49% respectively.The structural analysis indicated that C3 was catechol,and C4 maybe 3-isopropoxy-5-methyl-phenol.It suggests that the polyphenols might be the main constitutes in SC3 with high antioxidant activity.