紫苏叶黄酮、多酚提取工艺优化及不同品种抗氧化活性比较

紫苏(Perilla frutescens (L.) Britt.)是食药两用植物之一，本研究为比较不同品种紫苏叶(‘韩国绿色PF1’，‘中国PF2’，‘韩国紫色PF3’，‘韩国双色PF4’，‘中国双色PF5’)中黄酮和多酚提取量，并探讨其体外抗氧化活性，利用单因素实验和正交试验法优化紫苏叶黄酮和多酚提取工艺。结果表明：最佳工艺参数为乙醇浓度75%、料液比1:80 g/mL、提取时间2 h、提取温度70℃，此提取条件下，黄酮、多酚提取量最高，分别为(16.82±0.60)和(80.42±2.66) mg/g。不同品种紫苏叶中，PF3的多酚提取量最高(17.77±0.29) mg/g,PF5黄酮提取量最高(80.42±2.66) mg/g。抗氧化活性结果表明，不同品种紫苏叶均具有良好的抗氧化活性，其中PF5的ABTS⁺自由基清除率(IC50 150.31±2.46μg/mL)、DPPH自由基清除能力(IC50 88.04±3.61μg/mL)及总还原能力最强(P<0.05)。相关性分析表明，多酚提取量与ABTS⁺自由基清除率、总还原力呈显...

Optimization of Extraction Process of Flavonoids and Polyphenols from Perilla frutescens (L.) Britt Leaves and Comparison of Antioxidant Activities of Different Varieties

Perilla frutescens (L.) Britt. is one of the edible and medicinal plants. The purpose of this study was to compare the flavonoids and polyphenols extracted from different varieties of P. frutescens leaves ('Korean green PF1', 'Chinese PF2', 'Korean purple PF3', 'Korean bicolor PF4', 'Chinese bicolor PF5'), and to explore their antioxidant activities in vitro. Optimization of extraction process of flavonoids and polyphenols from P. frutescens leaves was studied by single factor tests and orthogonal test. The results showed that the optimum parameters were ethanol concentration 75%, solid-liquid ratio 1:80 g/mL, extraction time 2 h, extraction temperature 70 ℃. Under these conditions, the extraction amount of flavonoids and polyphenols was the highest, which were (16.82±0.60) mg/g and (80.42±2.66) mg/g, respectively. Among different varieties of P. frutescens leaves, PF3 had the highest content of polyphenols (17.77±0.29) mg/g, PF5 had the highest content of flavonoids (80.42±2.66) mg/g. The results of antioxidant activity showed that the leaves of different varieties of P. frutescens had good antioxidant activity. Among them, the ABTS+ free radical scavenging rate (IC₅₀ 150.31±2.46 μg/mL), DPPH free radical scavenging ability (IC₅₀ 88.04±3.61 μg/mL) and total reducing power of PF5 were the strongest (P<0.05). Correlation analysis showed that polyphenol extraction amount was significantly correlated with ABTS+ free radical scavenging rate and total reducing power (P<0.05), flavonoids extraction amount was significantly correlated with DPPH free radical scavenging rate and ABTS+ free radical scavenging rate (P<0.05), and was extremely significant with total reducing power (P<0.01). This study would provide a theoretical basis for the development and utilization of different varieties of P. frutescens leaf resources.