不同提取剂对红花桑寄生叶抗氧化活性的影响

测定了红花桑寄生(寄主夹竹桃)叶的水、体积分数80%甲醇和体积分数80%丙酮3种提取物抗氧化活性.结果表明:3种溶剂提取物均具有自由基清除能力,在3种溶剂提取物中,体积分数80%丙酮提取物清除DPPH自由基能力最强(ρEC50=0.306mg/mL),抗氧化能力最强,FRAP和TEAC值分别为0.81,1.62.3种提取物抗氧化活性从高至低依次为丙酮提取物、甲醇提取物、水提取物.此外,体积分数80%丙酮提取物中总酚(22.89%)和总黄酮(11.61%)也高于其他2种.可见,提取剂的性质对红花桑寄生叶提取物抗氧化活性的影响显著.

Effects of Different Extraction Solvents on the Antioxidant Activities of Leaves Extracts of Scurrula parasitica

Water,80% methanol and 80% acetone extracts of leaves of Scurrula parasitica (parasitic on Nerium indicum),were examined for their antioxidant activities by various assay.All leaves extracts were capable of free radicals scavenging activities. Among three solvent extracts of S.parasitica leaves,80% acetone extract showed the highest DPPH radical scavenging capacity with the value of ρ_(EC50) 0.306 mg/mL,and had the strongest antioxidant activity at 0.81 and 1.62 for FRAP and TEAC assays. The antioxidant activities of different extracts were in this order:80% acetone extract,methanol extract,water extract. In addition,80% acetone extract contained more phenolics (22.89%) and flavonoids(11.61%) than the other two extracts. Therefore,the properties of the extracting solvents significantly affected the antioxidant activity of leaf extract from S.parasitica.