大飞扬总黄酮提取工艺优化及抗氧化活性测定

Determination of extraction process and antioxidant activity of the total flavonoids from Euphorbia hirta

关键词:  大飞扬  总黄酮  正交试验  超声提取法  抗氧化活性

Key words:  Euphorbia hirta  total flavonoids  orthogonal test  ultrasonic extraction  antioxidant activity

摘要:

大飞扬为大戟科(Euphorbiaceae)大戟属(Euphorbia)植物飞扬草(E. hirta),主要化学成分为黄酮类、丹宁类、三萜类、二萜类,具有清热解毒、利湿止痒、通乳等功效。目前对大飞扬的研究主要集中在化学成分及药理活性的研究,对黄酮类成分提取工艺优化报道较少。为优化大飞扬总黄酮的提取工艺,该文以采自海南儋州的野生大飞扬干燥全草为材料,以总黄酮产率为评价指标,在单因素试验的基础上,进一步通过正交试验设计对大飞扬总黄酮的提取工艺进行优化,同时采用清除DPPH自由基及ABTS法对其抗氧化活性进行测定。结果表明:大飞扬总黄酮最佳提取工艺为药材粉碎过4号筛(65目),以85%乙醇超声提取4次; 大飞扬总黄酮对DPPH和ABTS自由基均有较好的清除率作用,其IC₅₀值分别为56.1和60.7 μg/mL。大飞扬黄酮类成分大多具有酚羟基基团,如异鼠李素、槲皮素等,具有较好的抗氧化活性。该文结果为大飞扬中黄酮类成分工业化生产提供了依据,也为进一步开发利用大飞扬药材奠定了基础

Abstract:

Euphorbiahirta(Euphorbia)which contains flavonoids,tannins,triterpenes,diterpenes,possesses various effects such as heat-clearing and detoxicating,damping elimination and relieving itch and promoting lactation. The current research of E. hirta has been mainly focused on the study of chemical constituents and pharmacological activities. However,there is little report about the optimization of extraction process of flavonoids. In this study,the dry herb of wild E. hirta as experimental material was collected from Danzhou,Hainan Province. To optimize the extraction technology of total flavonoids of E. hirta,the total yield of flavonoids was evaluated by the single factor experiment and orthogonal experimental design. In addition,the antioxidant activity of flavonoids from E. hirta was measured by using DPPH and ABTS radical scavenging. The result displayed the optimal extraction method which was as follows: the powder of E. hirta was extracted by ultrasonic extractor for 4 times with 85% ethanol after being sieved by No.4 sieve(65 meshes). The rate of DPPH and ABTS radical scavenging gradually increased as the concentration of flavonoids from E. hirta increased,(IC₅₀ was 56.1 and 60.7 μg/mL,respectively). The flavonoids of E. hirta has a better antioxidant activity due to its phenolic hydroxyl groups like isorhamnetin. The results would provide a basis for the industrial production of the flavonoids of E. hirta,and lay the foundations for the further exploitation and utilization of the medicinal materials E. hirta.