不同精致工艺杜仲枝木醋液抑菌及抗氧化活性比较

Research on Antimicrobial and Antioxidant Activities of Pyroligneous Acids of Eucommia ulmoides Branch Dealing with Different Refined Methods

以杜仲枝木为材料，利用高温回转炉在550℃下制备杜仲枝木粗木醋液，通过超低温冷冻解冻法、活性炭吸附法处理后，得2组精制杜仲木醋液，杜仲粗木醋液和2组精致木醋液分别记为DC550、DL550、DX550，并对3组木醋液抑菌活性和抗氧化活性进行测定。结果表明：3组木醋液均有抑菌活性和抗氧化活性，其抑菌活性顺序为DC550〉DL550〉DX550，且3组木醋液对不同供试菌种的抑制效果的差异显著性不同；DC550对植物病原菌的EG50为0．77～1．52mg／g。对DPPH·自由基、ABTS·自由基清除能力均低于抗坏血酸（Vo），大小顺序为V。〉DC550〉DL550〉DX550，3组木醋液总酚含量大小顺序与抗氧化活性大小顺序一致。初步分析DC550具有较强的抗氧化活性和抑菌活性，这一特性与其总酚含量和有机酸含量较高有关。

Pyroligneous acid was prepared from the pyrolysis of Eucommia ulmoides branches at 550℃. The obtained acid （DC550） was refined by cryogenic freezing and activated carbon adsorption methods, re- sulted in 2 acids （DL550 and DX550）. Anti-microbial and antioxidant activities were measured. The re- sults demonstrated that the three acids all exhibited antioxidant and anti-microbial activities. The order of antimicrobial activity was DC550 〉 DL550 〉 DX550. Differences were observed in anti-microbial activity among the acid groups, and microbial tested. The range of ECso to plant pathogens was 0.77-1.52 mg/g in DC550. The free radical scavenging capabilities of three acids were all weaker than that of Vc, and the order was Vc 〉 DC550 〉 DL550 〉 DX550. Correlations were observed between phenol contents in the acids and antioxidant activity. DC550 in which the contents of phenols and acid were high presented the highest antioxidant and anti-microbial activity.