银杏外种皮杀螨活性物质的分离纯化研究

Isolation and purification of the acaricidal principal from external seed coat of Ginkgo biloba

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，L（k=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，L％及LC如作为活性筛选指标，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。

The strong acaricidal activity of the extract by 90% ethyl alocohol from the external seed coat of Ginkgo biloba L seeds against Panonychns cirri （Mcg）was reported here for the first time （LC50= 48.3mg/L, LC90= 94.1mng/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.