5种植物乙醇提取物抑菌杀虫活性

Antibacterial and Insecticidal Activities of Ethanol Plant Extracts

【目的】研究5种植物乙醇提取物的抑菌杀虫活性,并对杀蝗活性最高的闹羊花提取物进行活性物质的分离,为进一步研究其杀蝗活性物质的结构和其作用机理提供参考。【方法】筛选铁棒锤Aconitum Pendulum、肉豆蔻Myristica fragrans Houtt、(紫丱子)紫铆Butea monosperma (Lan.)Kuntze、翼首草Pterocephalus hookeri和闹羊花Rhododendron mole 5种植物乙醇提取物,分别测定其对植物病原真菌的抑制活性,对蚜虫和东亚飞蝗的毒力;采用连续分级萃取法和柱层析法分离闹羊花的杀蝗活性物质。【结果】肉豆蔻提取物在1 000mg·L^-1质量浓度下对番茄绵腐病菌、苹果轮纹病菌和水稻纹枯病菌的抑制率分别为75.23%、77.78%和88.85%;48h后闹羊花提取物在2 000mg·L^-1质量浓度下对蚜虫的致死率为55.38%,10 000mg·L^-1下的致死率为100%;闹羊花提取物在10 000mg·L^-1质量浓度下,24h后对蝗虫的致死率为44.83%,96h后的致死率为86.96%。从闹羊花提取物中分离得到的活性物质流分Ⅲ-2-2,在1 000mg·L^-1质量浓度下,24h后对蝗虫的致死率为53.57%,120h后的致死率为90.48%。【结论】肉豆蔻提取物的抑菌活性最高;闹羊花提取物对蚜虫和蝗虫的毒杀活性最高;闹羊花提取物中杀蝗活性物质集中在石油醚萃取物和二氯甲烷萃取物,从二氯甲烷萃取物中分离得到对蝗虫毒杀活性最高的流分Ⅲ-2-2。

【Objective】Ethanol extracts of 5 species of plants were analyzed for possible antibacterial and/or insecticidal applications in disease control.【Method】Aconitum Pendulum,nutmeg(Myristica fragrans Houtt),Butea monosperma(Lan.)Kuntze,Pterocephalus hookeri,and Rhododendron molle were selected for the extraction.The inhibitory activities of the extracts against plant pathogenic fungi as well as the virulence to aphids and locusts were determined.Subsequently,the greatest locust-killing capacity demonstrated by the R.molle extract was subjected to a step-wise fractional extraction and column separations to isolate active substances.【Result】The nutmeg extract applied at 1 000 mg·L^-1 level inhibited the growth of Pythium aphanidermatum,Physalospora berengeriana and Rhizoctonia solani at 75.23%,77.78% and 88.85%,respectively.The R.molle extract showed the lethality on aphids at a rate of 55.38% with the dosage of 2 000 mg·L^-1 and 100% with 10 000 mg·L^-1 in 48 h;while that on locusts,44.83%in 24 hand 86.96%in 96 hwith 10 000 mg·L^-1.At 1 000 mg·L^-1 dosage,the active fraction,III-2-2,isolated from the extract rendered the lethal rates on locusts of 53.57%in24 hand 90.48% in 120 h.【Conclusion】The antibacterial activity of nutmeg extract was the highest among all extracts;the R.molle extract displayed the highest toxicity on aphids and locusts;most of the active substances in the extracts were petroleum ether and dichloromethane soluble;and,III-2-2 obtained from the dichloromethane fraction had the highest potency toward locusts.