金缕半枫荷多酚提取及其抗氧化抗菌活性研究

Extraction technology and antioxidant and antibacterial activities of polyphenols from Semiliquidambar cathayensis

关键词:  金缕半枫荷, 多酚, 抗氧化能力, 抗菌活性, DPPH·, 羟自由基

Key words:  Semiliquidambar cathayensis, polyphenols, antioxidant capacity, antibacterial activities, DPPH·, hydroxyl radical

摘要:

为进一步开发和利用金缕半枫荷,该研究以超声时间、液料比、乙醇体积分数和超声温度为考察因素,用金缕半枫荷总多酚提取率作为评价指标,采用单因素和正交试验优化提取工艺确定最佳工艺,并以最佳工艺制备金缕半枫荷多酚; 进一步采用DPPH·和羟自由基清除法评价金缕半枫荷多酚的抗氧化能力,以抑菌圈和最小抑菌浓度(MIC)为指标,采用牛津杯和肉汤稀释法考察其抗菌活性。结果表明:最佳提取工艺为乙醇浓度70%,料液比为1:16,提取时间为60 min,提取温度为60 ℃。金缕半枫荷多酚清除DPPH·自由基的IC₅₀为 5.22 μg·mL^-1,与阳性对照维生素C的IC₅₀值4.31 μg·mL^-1无显著差异,羟自由基清除率IC₅₀为105 μg·mL^-1,显著低于维生素C的IC₅₀值(180 μg·mL^-1)。对金黄色葡萄球菌和大肠杆菌具有抑制作用,抑菌圈直径分别为(13.7 ± 1.2)mm和(10.0 ± 1.3)mm,MIC分别为0.393和0.785 mg·mL^-1。这表明金缕半枫荷多酚具有抗菌和显著抗氧化能力,为开发利用金缕半枫荷资源提供了理论依据。

Abstract:

In order to develop and utilize Semiliquidambar cathayensis, orthogonal design was used to explore the effects of ethanol content, liquid to solid ratio, extraction time and temperature. Moreover, the DPPH· and hydroxyl radical scavenging activities of the polyphenols were also investigated. The inhibition zone and minimal inhibitory concentration(MIC)were used to detect the antibacterial activities, and determined by Oxford Cup method and broth dilution method. The results were as follows: the best extraction condition was ethanol content of 70%, the solid to liquid ratio of 1:16, the extraction time of 60 min, and the extraction temperature of 60 ℃. In addition, there was no significant difference of the IC₅₀ value of DPPH· free radical scavenging between 5.22 μg·mL^-1 polyphenols and 4.31 μg·mL^-1 ascorbic acid. And the IC₅₀ value 105 μg·mL^-1of hydroxyl free radical scavenging of the polyphenols was significantly lower than that of ascorbic acid 180 μg·mL^-1. The results also showed that the polyphenols had antibacterial activity against Staphyloccocus aureus and Escherichia coli with the antibacterial circle were(13.7 ± 1.2)mm and(10.0 ± 1.3)mm, respectively. And the MIC were 0.393 and 0.785 mg·mL^-1, respectively. This research provides the theoretical information for further development and utilization of Semiliquidambar cathayensis resources.