白花丹根提取物的杀螨活性

研究了白花丹Plumbago zeylanica L. 根提取物对柑桔全爪螨的杀螨活性,发现其具有优良的杀螨、杀卵和产卵抑制活性.白花丹根先经甲醇冷浸提取,然后用石油醚萃取甲醇提取物,所得石油醚萃取物的12、24h杀螨致死中浓度(LC50)分别为2.52、2.12mg/ml, 产卵抑制中浓度(ODC50)分别为1.39、1.52mg/ml,杀卵LC50为1.04mg/ml.石油醚萃取物经硅胶柱层析后,以PE5-9馏份的活性最高,1mg/ml浓度下,杀螨率和杀卵率与白花丹素(plumbagin)标样在P=0.05水平均无显著差异.PE5-9馏份 12、24h的杀成螨LC50分别为0.71、0.67mg/ml,杀卵LC50为0.66mg/ml.不同溶剂展开系统薄层层析和GC-MS结果表明,该植物中的杀螨活性主要成分为白花丹素.

Acaricidal activity of root extracts of Plumbago zeylanica L

The acaricidal toxicity to adult mites and eggs,including inhibitory activity to female adult mites,of the root extract of Plumbago zeylanica L.was investigated under laboratory conditions.Root powder of was extracted with methanol at room temperature,then partitioned with petroleum ether.The petroleum ether fraction(PEF) was tested for toxic and oviposition deterrent properties against citrus red mite,Panonychus citri(McGregor).Citrus leaves treated with the PEF were offered to adult female mites and the LC50 for 12h and 24h were measured.It was found that PEF was highly toxic to female mites,its LC50 of 12h and 24h were 2.52mg/ml and 2.12mg/ml,respectively.PEF was also found effective in killing eggs and reducing the number of egg-laying,the median oviposition deterrent concentration(ODC50) at 12h and 24h were 1.39mg/ml and 1.52mg/ml,respectively.Its LC50 of egg mortality was 1.04mg/ml.By silica gel column chromatography,PE5-9 was obtained and found to be highly effective against mites.At 1mg/ml concentration,no significant difference of mites and eggs mortality was found between plumbagin and PE5-9.Further investigation revealed that LC50 of 12h and 24h of PE5-9 to female adult mites were 0.71mg/ml and 0.67 mg/ml.LC50 of PE5-9 was 0.66mg/ml.Results from TLC test with different developing solvent systems and GC-MS s-howed that plumbagin was the main active compound.