The Herbicidal Activity Of The Peel Of Sapindus Mukurossi

It is a focus for the study of botanical pesticides to find natural bio-active from plants.To isolate these compounds and to make use of them as new agrochemicals or leadingstructure of new agrochemicals is one of the hot spots now.Sapindus peel, a kind of traditional medicine herb that can be used in clinicalmedicine, has rarely used in agriculture as herbicide. as a traditional Chinese medicine, itsapplication more extensive use in daily chemical and environmental fields is also verybroad. In this study, a preliminary study of agricultural herbicidal activity of the seed peelextract of Sapindus; with Cynodon dactylon, Agrostis stolonifera, Poa annua, Trifoliumpretense and Lactuca stiva as indicator plants,research the methods of the extraction ofactive substances from seed peel of Sapindus; at the same time, The herbicidal activity ofits active substances was purified with active tracking method. The main results were asfollows:1. Four solvents (petroleum ether, ethyl acetate,95%ethanol, and distilled water)were used to extract seed peel of Sapindus, different polar solvents had different yield.Among them, the polarity of95%ethanol is higher, the yield of the extract was37.34%;the yield of ethyl acetate extract was9.78%, the polarity of the largest is distilled water, butthe yield of the extract was23.48%; the yield of petroleum ether extract only1%.Therefore, the polarity of the extraction solvent can directly affect the yield of the extractfrom seed peel of Sapindus.2. The phytotoxic effects on root growth of Sapindus seed peel extracts with4solvents (petroleum ether, ethyl acetate,95%ethanol, and distilled water) in the plantmodels (Cynodon dactylon, Agrostis stolonifera, Poa annua, Trifolium pratense,Lactucastiva) were investigated. Four solvents (petroleum ether, ethyl acetate,95%ethanol, anddistilled water) were used to extract plant samples, and the extracts were tested for theirherbicidal activities against tested plants by means of growth rate method. The resultsshowed that Sapindus seed peel extracts using different polar solvents had differentinhibition rates on the five tested plants. At the concentration of0.25g/L, the inhibitionrates of ethyl acetate extract on Lactuca stiva and Agrostis stolonifera were68.87%and75.33%, followed by95%ethanol, the inhibition rates were63.47%and47.17%, theinhibition rates of distilled water extract were56.5%and47.03%. Petroleum ether extractalmost no inhibition. The EC50(g/L) of the extract from each solvent were ranged from 0.0534g/L~0.0787g/L、0.0861g/L~0.1401g/L and0.2033g/L~0.5264g/L respectively forLactuca stiva and for Agrostis stolonifera were ranged from0.0479g/L~0.0721g/L、0.1425g/L~0.2902g/L and0.3258g/L~0.4985g/L respectively.3. Extracts of seed peel of Sapindus with different solvents were isolated by means ofphytochemistry combined with bioassay. The bioassay results showed that the flow of50%ethanol isolated from ethyl acetate extract by macroporous resin column chromatographyhave higher inhibition rate on the growth of Lactuca stiva and Agrostis stolonifera. At theconcentration of0.25g/L, the inhibition rates of the flow of50%ethanol isolated fromethyl acetate extract on Lactuca stiva and Agrostis stolonifera were49.87%and78.53%,with the EC50at0.1358g/L and0.0909g/L. The fractions of50%ethanol and70%ethanolisolated from95%ethanol extract by macroporous resin column chromatographypossessed higher inhibition rates. The inhibition rate of the fraction of50%on Lactucastiva and Agrostis stolonifera were70.93%and86.07%, with the EC50at0.0760g/L and0.0593g/L. The inhibition rate of the fraction of70%on Lactuca stiva and Agrostisstolonifera were62.73%and86.07%, with the EC50at0.0638g/L and0.0593g/L. Thefraction of70%ethanol isolated from distilled water extract by macroporous resin columnchromatography on Lactuca stiva and Agrostis stolonifera were70.27%and73.77%, withthe EC50at0.2333g/L and0.0527g/L.4. The fractions of50%ethanol isolated from95%ethanol extract by macroporousresin column chromatography possessed higher activities to the tested plants. The fractionsof50%ethanol was further isolated by gel column chromatogaphy and purified bythin-layer chromatography (TLC) and column chromatography, got two fractions and1fraction was confirmed a strong phytotoxic effect. The fraction was further isolated byMedium voltage preparative chromatography and analysis by thin-layer chromatography(TLC), got four fractions.1fraction was confirmed a strong phytotoxic effect. The EC50values were ranged from0.0492g/L~0.0858g/L on Lactuca stiva,0.0455g/L~0.0984g/Lon Agrostis stolonifera.