女贞子多酚对自由基的清除效果及其影响因素分析

Free Radical Scavenging Effect of Ligustrum lucidum Polyphenol and Analysis of Influence Factors

天然水溶性自由基清除剂包括酚类、维生素类、糖类、肽类等,其中自由基清除能力最强的是酚类。从新鲜女贞子中提取到的女贞子多酚极易氧化,具有显著的自由基清除作用。采用DPPH法研究了女贞子多酚对自由基的清除效果,并探讨了女贞子多酚浓度、反应时间、反应温度和女贞子采集时间对DPPH清除率的影响,比较了女贞子多酚与3种常用抗氧化剂的DPPH清除能力。结果表明,随着女贞子多酚浓度的增加、反应时间的延长和反应温度的升高,DPPH清除率逐渐升高;在女贞子多酚浓度为0.035 mg·mL^(-1)、反应时间为120 min、反应温度为30℃时,女贞子多酚对DPPH的清除率达100%;女贞子多酚与3种常用抗氧化剂的DPPH清除能力大小为:没食子酸>女贞子多酚>抗坏血酸>还原型谷胱甘肽;不同月份女贞子多酚提取物对自由基的清除能力差异明显,随着采集时间的推迟,DPPH清除率逐渐下降,在9~12月份采集的女贞子多酚提取物中,9月份采集的女贞子多酚提取物的自由基清除能力最强。

Natural water-soluble free radical scavengers include phenols, vitamins, sugars, and peptides, a-mong which the phenols have the strongest free radical scavenging ability. The polyphenol extracted from fresh Ligustrum lucidum can be easily oxidized and has significant free radical scavenging eradical scavenging effect of Ligustrum lucidum polyphenol by a DPPH method, investigated the effects of L ig u -strum lucidum polyphenol concentration, reaction time, reaction temperature, and collection time of Ligustrum lucidum on the DPPH scavenging rate,and compared the D P P H scavenging ability of Ligustrum lucidum poly-phenol and three common antioxidants. The results indicate that the D P P H scavengiincrease of polyphenol concentration,reaction time,and reaction temperature. The DPPH scavenging rate can reach 100% under the conditions as follows： the Ligustrum lucidum polyphenol concentration is 0. 035 mg· mL-1 , t he reaction time is 120 min , a nd the reaction temperature is 30°C . The DPPH scavenging abilities of Li-gustrum lucidum polyphenol and three common antioxidants are in the following order（frweaker） ： gallic acid, Ligustrum lucidum polyphenol , ascorbic acid , and reduced glutathione,The free radical scavenging abilities of Ligustrum lucidum polyph enol extracts in differentmon ths are significantly different.With the delay of collection time,the DPPH scavenging rate will gradually decrease. Among the Ligustrum lu-cidum polyphenoi ectracts collected in Beptember t5 December,the Mree radicai scavenHinH aSilitJ oM tie Ligus-trum lucidum polyphenols ectract s in Beptembe r is tFe strongest.