一年蓬提取物的抗菌活性

Antimicrobial activity of extracts from Erigeron annuus

为了研制安全、高效、经济的植物源杀菌剂,以入侵植物一年蓬(Erigeron annuus)为原料,2种植物病原真菌——黄瓜枯萎病菌(Fusarium oxysporium)和番茄早疫病菌(Alternaria solani)的抑制率为指标,通过单因素及响应面实验,优化得到一年蓬抑菌活性成分的最佳提取工艺:提取时间6 min、料液质量浓度1∶60 g/mL、提取温度60℃;所得提取物依次经石油醚、氯仿、乙酸乙酯、正丁醇萃取得各萃取相,其中乙酸乙酯相对2种病原菌抑制率均最高;乙酸乙酯对黄瓜枯萎病菌及番茄早疫病菌的最小抑菌浓度(MIC)分别为0.75,1.50 mg/mL,对2种病原菌的最小杀菌浓度(MBC)皆为36 mg/mL;经离体叶片实验,乙酸乙酯对黄瓜枯萎病和番茄早疫病均具有一定的预防和治疗效果.表明一年蓬提取物的乙酸乙酯相具有开发成植物源杀菌剂的潜力.

The chemical fungicides were regarded as efficient and economical fungicides, however, long-term usage of chemical fungicides would cause refractory degradation, pesticide residues, spread, environmental pollution, food safety issues and so on. In order to develop a kind of plant-derived fungicide with safe, efficient and economic features, Erigeron annuus of invasive plant were used as raw material. With inhibitory activity on two fungi Fusarium oxysporium and Alternaria solani as indicator, the optimal extraction conditions for E. annuus were determined as microwave power of 500 W, time of 6 min, solid-iquid ratio of 1 ∶ 60 g/mL, extraction temperature of 60 ℃. Under the optimal conditions, the water-soluble extracts of E. annuus were sequentially extracted with petroleum ether, chloroform, ethyl acetate and n-butyl alcohol. The ethyl acetate fractions showed the highest inhibitory activity on these two fungi, the minimal inhibition concentration ( MIC ) against F. oxysporium and A. solani were 0.75 mg/mL and 1.50 mg/mL, respectively. And minimal bactericidal concentration ( MBC ) against F. oxysporium and A. solani were both 36 mg/mL. Furthermore, its vivo assay showed good preventive and curative effects against cucumber wilt and tomato early blight. It was concluded that ethyl acetate fractions of the extract from E. annuus had the potential to develop into plant-derived fungicides.