玉米花粉提取物清除自由基活性研究

FREE RADICAL SCAVENGING ACTIVITIES OF MAIZE POLLEN EXTRACTS

用75%(体积分数)乙醇水溶液在室温下提取玉米花粉活性成分,浓缩后分成两部分,一部分被称为提取原液,另一部分依次用正己烷、乙酸乙酯、正丁醇萃取,分别浓缩得到正己烷相、乙酸乙酯相、正丁醇相和水相,分别研究它们对稳定N,N-二苯基三硝基苯肼自由基[DPPH·]和羟基自由基[·OH]的清除效果,并利用高压液相对各萃取相中的黄酮类进行分析,结果表明:玉米花粉的几种溶剂提取物对[DPPH·]自由基的清除能力存在较大差异,最强的是乙酸乙酯相,比芦丁和BHT还要强,最弱的是水相;对羟基自由基[·OH]的清除能力略有差异,其中乙酸乙酯相最强与芦丁相似,最弱的是水相。玉米花粉提取物的不同萃取相中,黄酮类存在较大差异,黄酮类可能是导致玉米花粉具有清除自由基能力的主要原因。

Maize pollen active constituents were extracted with 75 % ethanol/water （v/v） at room temperature. Extracts were concentrated and were separated into two parts.One part was called original liquid phase,the other part was extracted with n-hexane, ethyl acetate and n-bud alcohol,respectively.After they were respectively concentrated, n-hexane phase,ethyl acetate phase, n-bud alcohol and water phase were obtained.Their physiological functions of scavenging [·OH] and stable [DPPH·] were investigated.The flavonoids of all extracts were also analyzed by HPLC.Resuhs show that the scavenging [DPPH·] capacities of ethyl actate phase was the strongest among them, and the weakest is water phase. In the respect of scavenging [·OH] capacities, there is no significant difference among them. But ethyl actate phase exhibited relatively stronger activity, and the weakest is still water phase.The flavonoids of different extracts from maize pollen were different.Maybe it was a important cause leading to maize pollen own stronger free radical scavenging activities.