5种不同寄主来源的红花寄生叶提取物清除羟自由基的能力

Study on Hydroxyl Radical Scavenging Activities of Leaves Extracts of Scurrula parasitica Sourced from Five Different Host Trees

采用荧光法测定了寄生于夹竹桃、女贞、石榴、荷花玉兰和长梗柳等5种植物上的红花寄生不同溶剂(水、体积分数80%甲醇、体积分数80%丙酮)叶提取物对羟自由基的清除能力,结果表明:红花寄生叶提取物有清除羟自由基的活性,且清除能力的强弱受提取剂、不同寄主来源的影响显著.以体积分数80%甲醇和体积分数80%丙酮为溶剂获得的叶提取物对.OH的清除作用较强;在5种不同寄主来源的甲醇提取物中,以长梗柳、石榴和夹竹桃上寄生的清除能力较强,其ρEC50分别为0.220,0.264,0.272 mg.mL-1.此外,统计分析显示红花寄生叶提取物对羟自由基的清除能力与其总酚和总黄酮含量呈显著正相关,相关系数R2分别为0.705、0.640,表明提取物中酚性物质参与了清除羟自由基的反应.

The hydroxy radical scavenging capacity of different solvents （water, 80% methanol and 80 % acetone） of leaf extracts from Scurrula parasitica, parasitic on Nerium indicurn, Salix dunnii, Ligustrum lucidurn, Punica granatum, Magnolia grandiflora , were detected by fluorescence spectrophotometry. The result indicated that leaf extracts of S. parasitica exhibited scavenging activity on hydroxy radical, which was significantly affected by different extraction agent and host trees. Extracts of 80% methanol and 80% acetone had stonger hydroxy radical scavenging actvities than water extracts. Among the five different host trees, 80 ~ methanol extracts sourced from Salix dunnii, Punica granaturn and Nerium indicum showed higher radical-scanvenging with PEC50 values of 0. 220, 0. 264, 0. 272 mg · mL^-1 , respectively. In addition, a positive correlation was observed between scavenging capacity of extracts and polyphenol and flavonoid content with the correlation coefficientcontent of 0. 705, 0. 640, respectively. It indicated that phenolic substances of extracts contributed to the hydroxy radical scavenging reaction.