【摘要】 本文发现银杏外种皮90%乙醇粗提物对柑桔全爪螨具有高效的杀灭作用(LC50=48.3mg/L,LC90=94.1mg/L),且醇提物得率高达20.4%。同时发现外种皮水提物基本无杀螨作用(LC50=5295mg/L,LC90=29139mg/L)。对醇提物进行索氏分段,发现杀螨活性主要集中于极性较弱的60℃~90℃石油醚段中,其得率为87.2%。运用硅胶层析和Sephadex LH-20分子筛结合的分离纯化手段,LC50及LC90作为活性筛选指标,对60℃~90℃石油醚索提物进行分离纯化,得到一种高效杀螨活性的样品(LC50=5.3mg/L,LC90=13.1mg/L)。经高压液相分析,该样品纯度达到94.6%;经显色反应,初步确认其为有机酚酸类物质。更多还原

【Abstract】 The strong acaricidal activity of the extract by 90% ethyl alocohol from the external seed coat of Ginkgo biloba L seeds against Panonychus citri（Mcg）was reported here for the first time(LC₅₀=48.3mg/L,LC₉₀=94.1mg/L).Furthermore,its yield was 20.4%.While the extract by water showed no acaricidal activity(LC₅₀=5295mg/L,LC₉₀=29139mg/L).Among the soxhlet extractions of the extract by 90% ethyl alocohol,the strong acaricidal activity was only found to be in the non-polar fraction,petroleum ether（b.p.60-90℃） extract,which was 87.2%.The petroleum ether（b.p.60-90℃）extract was purified by means of combination silica gelchromatography and Sephadex LH-20 molecular sieve,using LC₅₀ and LC₉₀ as toxicity factors.Finally,a compound with high acaricidal activity(LC₅₀=5.3mg/L,LC₉₀=13.1mg/L)was obtained.HPLC showed that the purity of the compound was 94.3%.With some chemical reactions,the compound isolated was identified as a phenolic acid.Our work of purification may establish a foundation of the future work to analysis and identify the structure of the compound.更多还原