Antioxidant Properties Of Rehmannia Glutinosa Libosch And Screening For Suitable Herbicide

Determination of rehmannia extract on ultraviolet absorption peak characteristic by adopting ultraviolet absorption method,showed that the absorption peak were in196.0nm for the water extracts of fresh root and dry root in204.5nm for leaves water extract.The ethanol extract of fresh root had absorption peaks in394nm,373nm,353.5nm,290nm,275.5nm respectively.For dry root ethanol extract the peak were in396.5nm,376.0nm,283.0nm respectively.The leaves ethanol extract had absorption peak in217.0nm and fresh root diethyl ether extract had absorption peak in276.5nm and226.0nm respectively.For the diethyl ether extract of dry root,the absorption peak in240.0nm.The leaves diethyl ether extract had absorption peak in323.5nm,268.5nm and203.5nm respectively.The extractions of the rehmannia of fresh root, fresh leaves and dry root by the methods of DPPH dissolved ethanol,diethyl ether and water,respectively were used to identificate DPPH free radical scavenging rate.The result showed the DPPH scavenging activity was decreased in the order of95%ethanol,99.5%diethyl ether,water for fresh root extracts,99.5%diethyl ether>95%ethanol> water for fresh leaves extracts and water>95%ethanol>99.5%diethyl ether for dry root extracts.The best effect was the ethanol extraction of fresh root and the value of IC50is1.29.The weakest effect was ethyl ether extraction of dry root and the value of IC50is94.9.The determination of total flavonoids showed that70%ethanol as extracting agent was higher.The content of leaves was higher than root and the the value was2.29and1.59respectively.The result of determination of flavonoids ingredients with the liquid chromatography, the content of acteoside in the leaves extract is highest for7.015, forzen rehmannia root extract is lowest for0.011,the difference of acteoside content in the dry root methyl alcohol extract and dry root water and methanol mixed extract is small.Respectively for0.475and0.450.Detoxification effect test results of rehmannia extracts to strong oxidizing herbicide paraquat were that there were strong antioxidant activity of rehmannia extracts and natural ingredients acteoside and buddleoside in the rehmannia,they could reduce the poisoning symptoms of paraquat on soybean stem when mixed with paraquat. For screening of safety herbicides to rehmannia,several common herbicides were selected to conduct herbicides phytotoxicity identification of different period and dosages.To analyze the GC-MS prometryn residue to the dry root of rehmannia which through prometryn treatment with internal standard method.The result shows that it was safe to rehmannia when the dosage of prometryn used in the range from0.8to1.6kg (a.i.)/hm2. and the plant and fresh weight control effect of weeds was more than90%in the field of no malignant weeds.The result of residue determination was that the prometryn residues could reach0.059ppm when the dosage was1.6kg(a.i.)/hm,The prometryn residues was0.043ppm when the dosage was0.8kg(a.i.)/hm2.