桑叶乙醇提取物的体外抗氧化与抑菌活性

采用索氏提取法对干桑叶进行提取，得到乙醇提取物，并对提取物的组分以及体外抗氧化活性和抑菌活性进行了测定。研究结果表明：桑叶乙醇提取物中含有多种有机物，主要包括酯类(82.85%)、烷烃类(6.31%)、芳烃类(1.62%)和醇类(0.21%)。桑叶乙醇提取物总还原力与浓度有显著的线性关系；对DPPH自由基和OH自由基都有良好的清除能力，半数抑制浓度(IC₅₀)分别为73.07和104.52 mg/L。桑叶乙醇提取物对枯草芽孢杆菌、金黄色葡萄球菌和大肠杆菌均具有一定的抑制作用，抑制效果为枯草芽孢杆菌＞金黄色葡萄球菌＞大肠杆菌，IC₅₀分别为4.824、6.806和14.382 g/L。桑叶乙醇提取物的抗氧化活性和抑菌活性随样品浓度的增大而增大。

In Vitro Antioxidant and Antibacterial Activity of Ethanol Extract from Mulberry Leaves

Dry mulberry leaves was extracted by soxhlet extraction to obtain ethanol extract of mulberry leaves. And the composition, antioxidant activity and antibacterial activity of the ethanol extract of mulberry leaves in vitro were measured. The results showed that the ethanol extract of mulberry leaves contained many organics, including esters(82.85%), alkanes(6.31%), aromatic hydrocarbons(1.62%) and alcohols(0.21%). There was a significant linear relationship between the total reducing power and the concentration of ethanol extracts from mulberry leaves, and the extracts had good scavenging capacities of DPPH free radicals and OH free radicals with the half inhibitory concentrations(IC₅₀) of 73.07 and 104.52 mg/L, respectively. The ethanol extract of mulberry leaves had certain inhibitory effects on Bacillus subtilis, Staphylococcus aureus and Escherichia coli. Inhibitory effects were B. subtilis > S. aureus > E. coli, IC₅₀ were 4.824, 6.806 and 14.382 g/L, respectively. The antioxidant and antibacterial activity of the ethanol extract of mulberry leaves increased with the increase of sample concentration.