假蒟提取物杀虫活性成分稳定性研究

采用常规浸提法对假蒟植株根茎部分进行提取,以提取物中杀虫成分对斜纹夜蛾3龄幼虫的活性作为评价指标,综合评价了不同pH、不同温度和光照环境对假蒟提取物杀虫活性成分稳定性的影响。结果表明,不同pH环境对假蒟提取物杀虫活性成分影响不大;在高温环境中,其活性有所下降;在不同光源处理中,影响较为严重的是太阳光,经照射处理72h后,杀虫活性效果由93.33%变为27.78%。在此基础上,评价了11种常用光稳定剂的光分解抑制效果,结果发现,所评价的光稳定剂均具有一定抑制效果,其中以光稳定剂622和抗氧化剂TBHQ抑制效果较为明显。在此基础上,进一步评价了不同浓度622和TBHQ抑制效应差异,结果显示抑制效果与浓度相关,浓度越高,抑制效果越明显。

Stability of the insecticidal active constituents of the extract from Piper sarmentosum

Based on the effect of its components on Prodenia litura (Fabricius) 3rd instar larvae, the rhizomes of Piper sarmentosum Roxb. were extracted by using a conventional extraction approach, and the effects of different pH values, temperatures and light environments on the stability of the active components of its extractives were comprehensively evaluated. The results showed that the active components of P.sarmentosum were relatively stable at different pH values, and their activity had little change, but the activity declined with rising temperature; in the tests with different light sources, the activity was significantly influenced by sunlight; under the condition of sunlight for 72 h, its effect changed from 93.33% to 27.78%. Subsequently, we used 11 different light stabilizers to examine the inhibitory effect of photolysis, finding that different stabilizers all had some inhibitory effect, and that light stabilizer 622 and TBHQ were obviously effective. We also evaluated the effects of the light stabilizer 622 and TBHQ with different concentrations on the inhibition of P.sarmentosum, finding that the inhibitory effect was correlated with the concentration: the higher the concentration, the more obvious the inhibitory effect.